diff --git a/sources/OpenMcdf.Extensions/OLEProperties/Common.cs b/sources/OpenMcdf.Extensions/OLEProperties/Common.cs
index ba703681..b61ddcc9 100644
--- a/sources/OpenMcdf.Extensions/OLEProperties/Common.cs
+++ b/sources/OpenMcdf.Extensions/OLEProperties/Common.cs
@@ -1,6 +1,4 @@
-using System;
-
-namespace OpenMcdf.Extensions.OLEProperties
+namespace OpenMcdf.Extensions.OLEProperties
 {
     public enum Behavior
     {
diff --git a/sources/OpenMcdf.Extensions/OLEProperties/DictionaryEntry.cs b/sources/OpenMcdf.Extensions/OLEProperties/DictionaryEntry.cs
index bea8e286..3c691307 100644
--- a/sources/OpenMcdf.Extensions/OLEProperties/DictionaryEntry.cs
+++ b/sources/OpenMcdf.Extensions/OLEProperties/DictionaryEntry.cs
@@ -1,5 +1,4 @@
-using System;
-using System.IO;
+using System.IO;
 using System.Text;
 
 namespace OpenMcdf.Extensions.OLEProperties
diff --git a/sources/OpenMcdf.Extensions/OLEProperties/DictionaryProperty.cs b/sources/OpenMcdf.Extensions/OLEProperties/DictionaryProperty.cs
index 34021665..44cccfd3 100644
--- a/sources/OpenMcdf.Extensions/OLEProperties/DictionaryProperty.cs
+++ b/sources/OpenMcdf.Extensions/OLEProperties/DictionaryProperty.cs
@@ -21,8 +21,8 @@ public DictionaryProperty(int codePage)
 
         public object Value
         {
-            get { return entries; }
-            set { entries = (Dictionary<uint, string>)value; }
+            get => entries;
+            set => entries = (Dictionary<uint, string>)value;
         }
 
         public void Read(BinaryReader br)
diff --git a/sources/OpenMcdf.Extensions/OLEProperties/OLEPropertiesContainer.cs b/sources/OpenMcdf.Extensions/OLEProperties/OLEPropertiesContainer.cs
index a0558475..b565daf6 100644
--- a/sources/OpenMcdf.Extensions/OLEProperties/OLEPropertiesContainer.cs
+++ b/sources/OpenMcdf.Extensions/OLEProperties/OLEPropertiesContainer.cs
@@ -8,7 +8,7 @@ namespace OpenMcdf.Extensions.OLEProperties
 {
     public class OLEPropertiesContainer
     {
-        public Dictionary<uint, string> PropertyNames = null;
+        public Dictionary<uint, string> PropertyNames;
 
         public OLEPropertiesContainer UserDefinedProperties { get; private set; }
 
@@ -19,7 +19,7 @@ public class OLEPropertiesContainer
 
         public PropertyContext Context { get; }
 
-        private readonly List<OLEProperty> properties = new List<OLEProperty>();
+        private readonly List<OLEProperty> properties = new();
         internal CFStream cfStream;
 
         /*
@@ -98,7 +98,7 @@ internal OLEPropertiesContainer(CFStream cfStream)
             FmtID0 = pStream.FMTID0;
 
             PropertyNames = (Dictionary<uint, string>)pStream.PropertySet0.Properties
-                .Where(p => p.PropertyType == PropertyType.DictionaryProperty).FirstOrDefault()?.Value;
+                .FirstOrDefault(p => p.PropertyType == PropertyType.DictionaryProperty)?.Value;
 
             Context = new PropertyContext()
             {
@@ -149,7 +149,7 @@ internal OLEPropertiesContainer(CFStream cfStream)
                 }
 
                 var existingPropertyNames = (Dictionary<uint, string>)pStream.PropertySet1.Properties
-                    .Where(p => p.PropertyType == PropertyType.DictionaryProperty).FirstOrDefault()?.Value;
+                    .FirstOrDefault(p => p.PropertyType == PropertyType.DictionaryProperty)?.Value;
 
                 UserDefinedProperties.PropertyNames = existingPropertyNames ?? new Dictionary<uint, string>();
             }
@@ -224,7 +224,7 @@ public OLEProperty AddUserDefinedProperty(VTPropertyType vtPropertyType, string
         public void RemoveProperty(uint propertyIdentifier)
         {
             //throw new NotImplementedException("API Unstable - Work in progress - Milestone 2.3.0.0");
-            var toRemove = properties.Where(o => o.PropertyIdentifier == propertyIdentifier).FirstOrDefault();
+            var toRemove = properties.FirstOrDefault(o => o.PropertyIdentifier == propertyIdentifier);
 
             if (toRemove != null)
                 properties.Remove(toRemove);
diff --git a/sources/OpenMcdf.Extensions/OLEProperties/OLEProperty.cs b/sources/OpenMcdf.Extensions/OLEProperties/OLEProperty.cs
index 9bfa0921..85048f31 100644
--- a/sources/OpenMcdf.Extensions/OLEProperties/OLEProperty.cs
+++ b/sources/OpenMcdf.Extensions/OLEProperties/OLEProperty.cs
@@ -1,7 +1,4 @@
-
-using System;
-
-namespace OpenMcdf.Extensions.OLEProperties
+namespace OpenMcdf.Extensions.OLEProperties
 {
     public class OLEProperty
     {
@@ -47,10 +44,7 @@ public object Value
 
                 return value;
             }
-            set
-            {
-                this.value = value;
-            }
+            set => this.value = value;
         }
 
         public override bool Equals(object obj)
diff --git a/sources/OpenMcdf.Extensions/OLEProperties/PropertyFactory.cs b/sources/OpenMcdf.Extensions/OLEProperties/PropertyFactory.cs
index e66aa532..a787b8ae 100644
--- a/sources/OpenMcdf.Extensions/OLEProperties/PropertyFactory.cs
+++ b/sources/OpenMcdf.Extensions/OLEProperties/PropertyFactory.cs
@@ -54,7 +54,7 @@ protected virtual ITypedPropertyValue CreateLpstrProperty(VTPropertyType vType,
 
         #region Property implementations
 
-        private class VT_EMPTY_Property : TypedPropertyValue<object>
+        private sealed class VT_EMPTY_Property : TypedPropertyValue<object>
         {
             public VT_EMPTY_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -70,7 +70,7 @@ public override void WriteScalarValue(BinaryWriter bw, object pValue)
             }
         }
 
-        private class VT_I1_Property : TypedPropertyValue<sbyte>
+        private sealed class VT_I1_Property : TypedPropertyValue<sbyte>
         {
             public VT_I1_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -88,7 +88,7 @@ public override void WriteScalarValue(BinaryWriter bw, sbyte pValue)
             }
         }
 
-        private class VT_UI1_Property : TypedPropertyValue<byte>
+        private sealed class VT_UI1_Property : TypedPropertyValue<byte>
         {
             public VT_UI1_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -106,7 +106,7 @@ public override void WriteScalarValue(BinaryWriter bw, byte pValue)
             }
         }
 
-        private class VT_UI4_Property : TypedPropertyValue<uint>
+        private sealed class VT_UI4_Property : TypedPropertyValue<uint>
         {
             public VT_UI4_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -124,7 +124,7 @@ public override void WriteScalarValue(BinaryWriter bw, uint pValue)
             }
         }
 
-        private class VT_UI8_Property : TypedPropertyValue<ulong>
+        private sealed class VT_UI8_Property : TypedPropertyValue<ulong>
         {
             public VT_UI8_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -142,7 +142,7 @@ public override void WriteScalarValue(BinaryWriter bw, ulong pValue)
             }
         }
 
-        private class VT_I2_Property : TypedPropertyValue<short>
+        private sealed class VT_I2_Property : TypedPropertyValue<short>
         {
             public VT_I2_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -160,7 +160,7 @@ public override void WriteScalarValue(BinaryWriter bw, short pValue)
             }
         }
 
-        private class VT_UI2_Property : TypedPropertyValue<ushort>
+        private sealed class VT_UI2_Property : TypedPropertyValue<ushort>
         {
             public VT_UI2_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -178,7 +178,7 @@ public override void WriteScalarValue(BinaryWriter bw, ushort pValue)
             }
         }
 
-        private class VT_I4_Property : TypedPropertyValue<int>
+        private sealed class VT_I4_Property : TypedPropertyValue<int>
         {
             public VT_I4_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -196,7 +196,7 @@ public override void WriteScalarValue(BinaryWriter bw, int pValue)
             }
         }
 
-        private class VT_I8_Property : TypedPropertyValue<long>
+        private sealed class VT_I8_Property : TypedPropertyValue<long>
         {
             public VT_I8_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -214,7 +214,7 @@ public override void WriteScalarValue(BinaryWriter bw, long pValue)
             }
         }
 
-        private class VT_INT_Property : TypedPropertyValue<int>
+        private sealed class VT_INT_Property : TypedPropertyValue<int>
         {
             public VT_INT_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -232,7 +232,7 @@ public override void WriteScalarValue(BinaryWriter bw, int pValue)
             }
         }
 
-        private class VT_UINT_Property : TypedPropertyValue<uint>
+        private sealed class VT_UINT_Property : TypedPropertyValue<uint>
         {
             public VT_UINT_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -250,7 +250,7 @@ public override void WriteScalarValue(BinaryWriter bw, uint pValue)
             }
         }
 
-        private class VT_R4_Property : TypedPropertyValue<float>
+        private sealed class VT_R4_Property : TypedPropertyValue<float>
         {
             public VT_R4_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -268,7 +268,7 @@ public override void WriteScalarValue(BinaryWriter bw, float pValue)
             }
         }
 
-        private class VT_R8_Property : TypedPropertyValue<double>
+        private sealed class VT_R8_Property : TypedPropertyValue<double>
         {
             public VT_R8_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -286,7 +286,7 @@ public override void WriteScalarValue(BinaryWriter bw, double pValue)
             }
         }
 
-        private class VT_CY_Property : TypedPropertyValue<long>
+        private sealed class VT_CY_Property : TypedPropertyValue<long>
         {
             public VT_CY_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -307,7 +307,7 @@ public override void WriteScalarValue(BinaryWriter bw, long pValue)
             }
         }
 
-        private class VT_DATE_Property : TypedPropertyValue<DateTime>
+        private sealed class VT_DATE_Property : TypedPropertyValue<DateTime>
         {
             public VT_DATE_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -402,8 +402,6 @@ public override void WriteScalarValue(BinaryWriter bw, string pValue)
                     //if (addNullTerminator)
                     dataLength += 1;            // null terminator \u+0000
 
-                    var mod = dataLength % 4;       // pad to multiple of 4 bytes
-
                     bw.Write(dataLength);           // datalength of string + null char (unicode)
                     bw.Write(data);                 // string
 
@@ -418,7 +416,7 @@ public override void WriteScalarValue(BinaryWriter bw, string pValue)
             }
         }
 
-        protected class VT_Unaligned_LPSTR_Property : VT_LPSTR_Property
+        protected sealed class VT_Unaligned_LPSTR_Property : VT_LPSTR_Property
         {
             public VT_Unaligned_LPSTR_Property(VTPropertyType vType, int codePage, bool isVariant) : base(vType, codePage, isVariant)
             {
@@ -426,7 +424,7 @@ public VT_Unaligned_LPSTR_Property(VTPropertyType vType, int codePage, bool isVa
             }
         }
 
-        private class VT_LPWSTR_Property : TypedPropertyValue<string>
+        private sealed class VT_LPWSTR_Property : TypedPropertyValue<string>
         {
             private byte[] data;
             private readonly int codePage;
@@ -476,7 +474,7 @@ public override void WriteScalarValue(BinaryWriter bw, string pValue)
             }
         }
 
-        private class VT_FILETIME_Property : TypedPropertyValue<DateTime>
+        private sealed class VT_FILETIME_Property : TypedPropertyValue<DateTime>
         {
             public VT_FILETIME_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -495,7 +493,7 @@ public override void WriteScalarValue(BinaryWriter bw, DateTime pValue)
             }
         }
 
-        private class VT_DECIMAL_Property : TypedPropertyValue<decimal>
+        private sealed class VT_DECIMAL_Property : TypedPropertyValue<decimal>
         {
             public VT_DECIMAL_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -538,7 +536,7 @@ public override void WriteScalarValue(BinaryWriter bw, decimal pValue)
             }
         }
 
-        private class VT_BOOL_Property : TypedPropertyValue<bool>
+        private sealed class VT_BOOL_Property : TypedPropertyValue<bool>
         {
             public VT_BOOL_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -546,7 +544,7 @@ public VT_BOOL_Property(VTPropertyType vType, bool isVariant) : base(vType, isVa
 
             public override bool ReadScalarValue(BinaryReader br)
             {
-                propertyValue = br.ReadUInt16() == 0xFFFF ? true : false;
+                propertyValue = br.ReadUInt16() == 0xFFFF;
                 return (bool)propertyValue;
                 //br.ReadUInt16();//padding
             }
@@ -557,7 +555,7 @@ public override void WriteScalarValue(BinaryWriter bw, bool pValue)
             }
         }
 
-        private class VT_CF_Property : TypedPropertyValue<object>
+        private sealed class VT_CF_Property : TypedPropertyValue<object>
         {
             public VT_CF_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -585,7 +583,7 @@ public override void WriteScalarValue(BinaryWriter bw, object pValue)
             }
         }
 
-        private class VT_BLOB_Property : TypedPropertyValue<object>
+        private sealed class VT_BLOB_Property : TypedPropertyValue<object>
         {
             public VT_BLOB_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -612,7 +610,7 @@ public override void WriteScalarValue(BinaryWriter bw, object pValue)
             }
         }
 
-        private class VT_CLSID_Property : TypedPropertyValue<object>
+        private sealed class VT_CLSID_Property : TypedPropertyValue<object>
         {
             public VT_CLSID_Property(VTPropertyType vType, bool isVariant) : base(vType, isVariant)
             {
@@ -631,7 +629,7 @@ public override void WriteScalarValue(BinaryWriter bw, object pValue)
             }
         }
 
-        private class VT_VariantVector : TypedPropertyValue<object>
+        private sealed class VT_VariantVector : TypedPropertyValue<object>
         {
             private readonly int codePage;
             private readonly PropertyFactory factory;
@@ -681,7 +679,7 @@ internal sealed class DocumentSummaryInfoPropertyFactory : PropertyFactory
         protected override ITypedPropertyValue CreateLpstrProperty(VTPropertyType vType, int codePage, uint propertyIdentifier, bool isVariant)
         {
             // PIDDSI_HEADINGPAIR and PIDDSI_DOCPARTS use unaligned (unpadded) strings - the others are padded
-            if (propertyIdentifier == 0x0000000C || propertyIdentifier == 0x0000000D)
+            if (propertyIdentifier is 0x0000000C or 0x0000000D)
             {
                 return new VT_Unaligned_LPSTR_Property(vType, codePage, isVariant);
             }
diff --git a/sources/OpenMcdf.Extensions/OLEProperties/PropertySet.cs b/sources/OpenMcdf.Extensions/OLEProperties/PropertySet.cs
index 15bc2b5d..98aa9893 100644
--- a/sources/OpenMcdf.Extensions/OLEProperties/PropertySet.cs
+++ b/sources/OpenMcdf.Extensions/OLEProperties/PropertySet.cs
@@ -25,7 +25,7 @@ public void LoadContext(int propertySetOffset, BinaryReader br)
             var currPos = br.BaseStream.Position;
 
             PropertyContext = new PropertyContext();
-            var codePageOffset = (int)(propertySetOffset + PropertyIdentifierAndOffsets.Where(pio => pio.PropertyIdentifier == 1).First().Offset);
+            var codePageOffset = (int)(propertySetOffset + PropertyIdentifierAndOffsets.First(pio => pio.PropertyIdentifier == 1).Offset);
             br.BaseStream.Seek(codePageOffset, SeekOrigin.Begin);
 
             VTPropertyType vType = (VTPropertyType)br.ReadUInt16();
diff --git a/sources/OpenMcdf.Extensions/OLEProperties/PropertySetStream.cs b/sources/OpenMcdf.Extensions/OLEProperties/PropertySetStream.cs
index 0d3e316d..af0dc066 100644
--- a/sources/OpenMcdf.Extensions/OLEProperties/PropertySetStream.cs
+++ b/sources/OpenMcdf.Extensions/OLEProperties/PropertySetStream.cs
@@ -102,7 +102,7 @@ public void Read(BinaryReader br)
             }
         }
 
-        private class OffsetContainer
+        private sealed class OffsetContainer
         {
             public int OffsetPS { get; set; }
 
diff --git a/sources/OpenMcdf.Extensions/OLEProperties/ProperyIdentifiers.cs b/sources/OpenMcdf.Extensions/OLEProperties/ProperyIdentifiers.cs
index 01db834f..658c5f7c 100644
--- a/sources/OpenMcdf.Extensions/OLEProperties/ProperyIdentifiers.cs
+++ b/sources/OpenMcdf.Extensions/OLEProperties/ProperyIdentifiers.cs
@@ -1,5 +1,4 @@
-using System;
-using System.Collections.Generic;
+using System.Collections.Generic;
 
 namespace OpenMcdf.Extensions.OLEProperties
 {
@@ -16,7 +15,7 @@ public enum ContainerType
 
     public static class CommonIdentifiers
     {
-        public static Dictionary<uint, string> PropertyIdentifiersSummaryInfo = new Dictionary<uint, string>()
+        public static Dictionary<uint, string> PropertyIdentifiersSummaryInfo = new()
         {
             {0x00000001, "CodePageString" },
             {0x00000002, "PIDSI_TITLE" },
@@ -38,7 +37,7 @@ public static class CommonIdentifiers
             {0x00000013, "PIDSI_DOC_SECURITY" }
         };
 
-        public static Dictionary<uint, string> PropertyIdentifiersDocumentSummaryInfo = new Dictionary<uint, string>()
+        public static Dictionary<uint, string> PropertyIdentifiersDocumentSummaryInfo = new()
         {
             {0x00000001, "CodePageString" },
             {0x00000002, "PIDDSI_CATEGORY" },
diff --git a/sources/OpenMcdf.Extensions/OLEProperties/TypedPropertyValue.cs b/sources/OpenMcdf.Extensions/OLEProperties/TypedPropertyValue.cs
index f043b93c..febcdfd9 100644
--- a/sources/OpenMcdf.Extensions/OLEProperties/TypedPropertyValue.cs
+++ b/sources/OpenMcdf.Extensions/OLEProperties/TypedPropertyValue.cs
@@ -12,7 +12,7 @@ internal abstract class TypedPropertyValue<T> : ITypedPropertyValue
 
         public VTPropertyType VTType => _VTType;
 
-        protected object propertyValue = null;
+        protected object propertyValue;
 
         public TypedPropertyValue(VTPropertyType vtType, bool isVariant = false)
         {
@@ -23,7 +23,7 @@ public TypedPropertyValue(VTPropertyType vtType, bool isVariant = false)
 
         public PropertyDimensions PropertyDimensions { get; } = PropertyDimensions.IsScalar;
 
-        public bool IsVariant { get; } = false;
+        public bool IsVariant { get; }
 
         protected virtual bool NeedsPadding { get; set; } = true;
 
@@ -39,15 +39,9 @@ private static PropertyDimensions CheckPropertyDimensions(VTPropertyType vtType)
 
         public virtual object Value
         {
-            get
-            {
-                return propertyValue;
-            }
+            get => propertyValue;
 
-            set
-            {
-                propertyValue = value;
-            }
+            set => propertyValue = value;
         }
 
         public abstract T ReadScalarValue(BinaryReader br);
diff --git a/sources/OpenMcdf.Extensions/StreamDecorator.cs b/sources/OpenMcdf.Extensions/StreamDecorator.cs
index 01b6fe3f..646a4931 100644
--- a/sources/OpenMcdf.Extensions/StreamDecorator.cs
+++ b/sources/OpenMcdf.Extensions/StreamDecorator.cs
@@ -9,7 +9,7 @@ namespace OpenMcdf.Extensions
     public class StreamDecorator : Stream
     {
         private readonly CFStream cfStream;
-        private long position = 0;
+        private long position;
 
         /// <summary>
         /// Create a new <see cref="StreamDecorator"/> for the specified <seealso cref="CFStream"/>.
diff --git a/sources/OpenMcdf/CFItem.cs b/sources/OpenMcdf/CFItem.cs
index 5fd4fe58..85203a93 100644
--- a/sources/OpenMcdf/CFItem.cs
+++ b/sources/OpenMcdf/CFItem.cs
@@ -163,14 +163,11 @@ public string Name
         /// </summary>
         public DateTime CreationDate
         {
-            get
-            {
-                return DateTime.FromFileTimeUtc(BitConverter.ToInt64(DirEntry.CreationDate, 0));
-            }
+            get => DateTime.FromFileTimeUtc(BitConverter.ToInt64(DirEntry.CreationDate, 0));
 
             set
             {
-                if (DirEntry.StgType != StgType.StgStream && DirEntry.StgType != StgType.StgRoot)
+                if (DirEntry.StgType is not StgType.StgStream and not StgType.StgRoot)
                     DirEntry.CreationDate = BitConverter.GetBytes(value.ToFileTimeUtc());
                 else
                     throw new CFException("Creation Date can only be set on storage entries");
@@ -182,14 +179,11 @@ public DateTime CreationDate
         /// </summary>
         public DateTime ModifyDate
         {
-            get
-            {
-                return DateTime.FromFileTimeUtc(BitConverter.ToInt64(DirEntry.ModifyDate, 0));
-            }
+            get => DateTime.FromFileTimeUtc(BitConverter.ToInt64(DirEntry.ModifyDate, 0));
 
             set
             {
-                if (DirEntry.StgType != StgType.StgStream && DirEntry.StgType != StgType.StgRoot)
+                if (DirEntry.StgType is not StgType.StgStream and not StgType.StgRoot)
                     DirEntry.ModifyDate = BitConverter.GetBytes(value.ToFileTimeUtc());
                 else
                     throw new CFException("Modify Date can only be set on storage entries");
@@ -201,10 +195,7 @@ public DateTime ModifyDate
         /// </summary>
         public Guid CLSID
         {
-            get
-            {
-                return DirEntry.StorageCLSID;
-            }
+            get => DirEntry.StorageCLSID;
             set
             {
                 if (DirEntry.StgType != StgType.StgStream)
diff --git a/sources/OpenMcdf/CFStream.cs b/sources/OpenMcdf/CFStream.cs
index c8ed35bc..abf00f2f 100644
--- a/sources/OpenMcdf/CFStream.cs
+++ b/sources/OpenMcdf/CFStream.cs
@@ -6,7 +6,6 @@
  *
  * The Initial Developer of the Original Code is Federico Blaseotto.*/
 
-using System;
 using System.IO;
 
 namespace OpenMcdf
diff --git a/sources/OpenMcdf/CompoundFile.cs b/sources/OpenMcdf/CompoundFile.cs
index e1fee2eb..9d4e2de1 100644
--- a/sources/OpenMcdf/CompoundFile.cs
+++ b/sources/OpenMcdf/CompoundFile.cs
@@ -11,7 +11,6 @@
 using RedBlackTree;
 using System;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.IO;
 
 namespace OpenMcdf
@@ -152,17 +151,16 @@ public class CompoundFile : IDisposable
         /// <summary>
         /// Flag for sector recycling.
         /// </summary>
-        private bool sectorRecycle = false;
+        private bool sectorRecycle;
 
         /// <summary>
         /// Flag for unallocated sector zeroing out.
         /// </summary>
-        private bool eraseFreeSectors = false;
+        private bool eraseFreeSectors;
 
         public bool ValidationExceptionEnabled { get; private set; } = true;
 
         private readonly CFSUpdateMode updateMode = CFSUpdateMode.ReadOnly;
-        private string fileName = string.Empty;
 
         /// <summary>
         /// Initial capacity of the flushing queue used
@@ -176,7 +174,7 @@ public class CompoundFile : IDisposable
         /// </summary>
         private const int FLUSHING_BUFFER_MAX_SIZE = 1024 * 1024 * 16;
 
-        private SectorCollection sectors = new SectorCollection();
+        private SectorCollection sectors = new();
 
         /// <summary>
         /// CompoundFile header
@@ -186,7 +184,7 @@ public class CompoundFile : IDisposable
         /// <summary>
         /// Compound underlying stream. Null when new CF has been created.
         /// </summary>
-        internal Stream sourceStream = null;
+        internal Stream sourceStream;
 
         /// <summary>
         /// Create a blank, version 3 compound file.
@@ -644,8 +642,6 @@ private void Load(Stream stream)
 
         private void LoadFile(string fileName)
         {
-            this.fileName = fileName;
-
             FileAccess access = updateMode == CFSUpdateMode.ReadOnly ? FileAccess.Read : FileAccess.ReadWrite;
             FileShare share = updateMode == CFSUpdateMode.ReadOnly ? FileShare.ReadWrite : FileShare.Read;
             FileStream fs = new(fileName, FileMode.Open, access, share);
@@ -952,9 +948,9 @@ private void AllocateSectorChain(List<Sector> sectorChain)
             AllocateFATSectorChain(sectorChain);
         }
 
-        internal bool _transactionLockAdded = false;
+        internal bool _transactionLockAdded;
         internal int _lockSectorId = -1;
-        internal bool _transactionLockAllocated = false;
+        internal bool _transactionLockAllocated;
 
         /// <summary>
         /// Check for transaction lock sector addition and mark it in the FAT.
@@ -1084,7 +1080,7 @@ private void AllocateDIFATSectorChain(List<Sector> FATsectorChain)
                     s.Type = SectorType.DIFAT;
                     s.Id = sectors.Count - 1;
                     difatSectors.Add(s);
-                    
+
                 }
             }
 
@@ -1212,7 +1208,7 @@ List<Sector> result
                     // a specification point of view:
                     // only ENDOFCHAIN should break DIFAT chain but
                     // a lot of existing compound files use FREESECT as DIFAT chain termination
-                    if (nextSecID == Sector.FREESECT || nextSecID == Sector.ENDOFCHAIN) break;
+                    if (nextSecID is Sector.FREESECT or Sector.ENDOFCHAIN) break;
 
                     validationCount--;
 
@@ -1427,10 +1423,11 @@ List<Sector> result
                     if (nextSecID == Sector.ENDOFCHAIN)
                         break;
 
-                    Sector ms = new Sector(Sector.MINISECTOR_SIZE, sourceStream);
-
-                    ms.Id = nextSecID;
-                    ms.Type = SectorType.Mini;
+                    Sector ms = new Sector(Sector.MINISECTOR_SIZE, sourceStream)
+                    {
+                        Id = nextSecID,
+                        Type = SectorType.Mini
+                    };
 
                     miniStreamView.Seek(nextSecID * Sector.MINISECTOR_SIZE, SeekOrigin.Begin);
                     miniStreamView.ReadExactly(ms.GetData(), 0, Sector.MINISECTOR_SIZE);
@@ -1783,20 +1780,15 @@ public void Save(Stream stream)
                 {
                     Sector s = sectors[i];
 
-                    if (s == null)
+                    // Load source (unmodified) sectors
+                    // Here we have to ignore "Dirty flag" of
+                    // sectors because we are NOT modifying the source
+                    // in a differential way but ALL sectors need to be
+                    // persisted on the destination stream
+                    s ??= new Sector(sSize, sourceStream)
                     {
-                        // Load source (unmodified) sectors
-                        // Here we have to ignore "Dirty flag" of
-                        // sectors because we are NOT modifying the source
-                        // in a differential way but ALL sectors need to be
-                        // persisted on the destination stream
-                        s = new Sector(sSize, sourceStream)
-                        {
-                            Id = i
-                        };
-
-                        //sectors[i] = s;
-                    }
+                        Id = i
+                    };
 
                     stream.Write(s.GetData(), 0, sSize);
 
@@ -2320,7 +2312,7 @@ public void Dispose()
 
         #endregion
 
-        private readonly object lockObject = new object();
+        private readonly object lockObject = new();
 
         /// <summary>
         /// When called from user code, release all resources, otherwise, in the case runtime called it,
@@ -2349,7 +2341,6 @@ protected virtual void Dispose(bool disposing)
                             header = null;
                             directoryEntries.Clear();
                             directoryEntries = null;
-                            fileName = null;
                             //this.lockObject = null;
 #if !FLAT_WRITE
                             this.buffer = null;
@@ -2370,7 +2361,7 @@ protected virtual void Dispose(bool disposing)
         internal bool IsClosed { get; private set; }
 
         private List<IDirectoryEntry> directoryEntries
-            = new List<IDirectoryEntry>();
+            = new();
 
         internal IList<IDirectoryEntry> Directories => directoryEntries;
 
@@ -2554,23 +2545,22 @@ public static void ShrinkCompoundFile(string fileName)
         /// <param name="currDstStorage">Current cloned destination storage</param>
         private static void DoCompression(CFStorage currSrcStorage, CFStorage currDstStorage)
         {
-            Action<CFItem> va =
-                delegate (CFItem item)
+            void va(CFItem item)
+            {
+                if (item.IsStream)
                 {
-                    if (item.IsStream)
-                    {
-                        CFStream itemAsStream = item as CFStream;
-                        CFStream st = currDstStorage.AddStream(itemAsStream.Name);
-                        st.SetData(itemAsStream.GetData());
-                    }
-                    else if (item.IsStorage)
-                    {
-                        CFStorage itemAsStorage = item as CFStorage;
-                        CFStorage strg = currDstStorage.AddStorage(itemAsStorage.Name);
-                        strg.CLSID = itemAsStorage.CLSID;
-                        DoCompression(itemAsStorage, strg); // recursion, one level deeper
-                    }
-                };
+                    CFStream itemAsStream = item as CFStream;
+                    CFStream st = currDstStorage.AddStream(itemAsStream.Name);
+                    st.SetData(itemAsStream.GetData());
+                }
+                else if (item.IsStorage)
+                {
+                    CFStorage itemAsStorage = item as CFStorage;
+                    CFStorage strg = currDstStorage.AddStorage(itemAsStorage.Name);
+                    strg.CLSID = itemAsStorage.CLSID;
+                    DoCompression(itemAsStorage, strg); // recursion, one level deeper
+                }
+            }
 
             currSrcStorage.VisitEntries(va, false);
         }
diff --git a/sources/OpenMcdf/DirectoryEntry.cs b/sources/OpenMcdf/DirectoryEntry.cs
index 5a4e1b32..3cea8928 100644
--- a/sources/OpenMcdf/DirectoryEntry.cs
+++ b/sources/OpenMcdf/DirectoryEntry.cs
@@ -102,16 +102,11 @@ public void SetEntryName(string entryName)
         }
 
         private ushort nameLength;
+
         public ushort NameLength
         {
-            get
-            {
-                return nameLength;
-            }
-            set
-            {
-                throw new NotImplementedException();
-            }
+            get => nameLength;
+            set => throw new NotImplementedException();
         }
 
         public StgType StgType { get; set; } = StgType.StgInvalid;
@@ -129,14 +124,8 @@ private Guid storageCLSID
 
         public Guid StorageCLSID
         {
-            get
-            {
-                return storageCLSID;
-            }
-            set
-            {
-                storageCLSID = value;
-            }
+            get => storageCLSID;
+            set => storageCLSID = value;
         }
 
         public int StateBits { get; set; }
@@ -333,28 +322,16 @@ public RedBlackTree.IRBNode Right
 
         public RedBlackTree.Color Color
         {
-            get
-            {
-                return (RedBlackTree.Color)StgColor;
-            }
-            set
-            {
-                StgColor = (StgColor)value;
-            }
+            get => (RedBlackTree.Color)StgColor;
+            set => StgColor = (StgColor)value;
         }
 
-        private IDirectoryEntry parent = null;
+        private IDirectoryEntry parent;
 
         public RedBlackTree.IRBNode Parent
         {
-            get
-            {
-                return parent;
-            }
-            set
-            {
-                parent = value as IDirectoryEntry;
-            }
+            get => parent;
+            set => parent = value as IDirectoryEntry;
         }
 
         public RedBlackTree.IRBNode Grandparent()
diff --git a/sources/OpenMcdf/Header.cs b/sources/OpenMcdf/Header.cs
index a20626a2..a67dd655 100644
--- a/sources/OpenMcdf/Header.cs
+++ b/sources/OpenMcdf/Header.cs
@@ -147,7 +147,7 @@ public void Read(Stream stream)
 
         private void CheckVersion()
         {
-            if (MajorVersion != 3 && MajorVersion != 4)
+            if (MajorVersion is not 3 and not 4)
                 throw new CFFileFormatException("Unsupported Binary File Format version: OpenMcdf only supports Compound Files with major version equal to 3 or 4 ");
         }
 
diff --git a/sources/OpenMcdf/Sector.cs b/sources/OpenMcdf/Sector.cs
index 324e4270..838fa79d 100644
--- a/sources/OpenMcdf/Sector.cs
+++ b/sources/OpenMcdf/Sector.cs
@@ -30,9 +30,9 @@ internal sealed class Sector
         public const int FATSECT = unchecked((int)0xFFFFFFFD);
         public const int DIFSECT = unchecked((int)0xFFFFFFFC);
 
-        public bool DirtyFlag { get; set; } = false;
+        public bool DirtyFlag { get; set; }
 
-        public bool IsStreamed => (stream != null && Size != MINISECTOR_SIZE) ? (Id * Size) + Size < stream.Length : false;
+        public bool IsStreamed => (stream != null && Size != MINISECTOR_SIZE) && (Id * Size) + Size < stream.Length;
 
         private readonly Stream stream;
 
@@ -53,7 +53,7 @@ public Sector(int size)
 
         public int Id { get; set; } = -1;
 
-        public int Size { get; private set; } = 0;
+        public int Size { get; private set; }
 
         private byte[] data;
 
diff --git a/sources/OpenMcdf/SectorCollection.cs b/sources/OpenMcdf/SectorCollection.cs
index 82a4e5a9..a1f3e2f9 100644
--- a/sources/OpenMcdf/SectorCollection.cs
+++ b/sources/OpenMcdf/SectorCollection.cs
@@ -31,7 +31,7 @@ internal sealed class SectorCollection : IList<Sector>
         public event Ver3SizeLimitReached OnVer3SizeLimitReached;
 
         private readonly List<List<Sector>> largeArraySlices = new();
-        private bool sizeLimitReached = false;
+        private bool sizeLimitReached;
 
         public SectorCollection()
         {
@@ -125,7 +125,7 @@ public void CopyTo(Sector[] array, int arrayIndex)
             throw new NotImplementedException();
         }
 
-        public int Count { get; private set; } = 0;
+        public int Count { get; private set; }
 
         public bool IsReadOnly => false;
 
diff --git a/sources/OpenMcdf/StreamView.cs b/sources/OpenMcdf/StreamView.cs
index ca31b912..8a303c8f 100644
--- a/sources/OpenMcdf/StreamView.cs
+++ b/sources/OpenMcdf/StreamView.cs
@@ -21,8 +21,8 @@ internal sealed class StreamView : Stream
 
         private long position;
         private readonly Stream stream;
-        private readonly bool isFatStream = false;
-        private readonly List<Sector> freeSectors = new List<Sector>();
+        private readonly bool isFatStream;
+        private readonly List<Sector> freeSectors = new();
         public IEnumerable<Sector> FreeSectors => freeSectors;
 
         public StreamView(List<Sector> sectorChain, int sectorSize, Stream stream)
@@ -85,7 +85,7 @@ public override int Read(byte[] buffer, int offset, int count)
             count = Math.Min((int)intMax, count);
 
             // Ensure read request greater then stream length, when position is not 0, return only the limited and correct number of bytes
-            count = (int)Math.Min(length - position, count);  
+            count = (int)Math.Min(length - position, count);
 
             if (BaseSectorChain != null && BaseSectorChain.Count > 0)
             {
@@ -325,4 +325,4 @@ public override void Write(byte[] buffer, int offset, int count)
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/sources/Structured Storage Explorer/MainForm.cs b/sources/Structured Storage Explorer/MainForm.cs
index 83776c17..718d04cf 100644
--- a/sources/Structured Storage Explorer/MainForm.cs	
+++ b/sources/Structured Storage Explorer/MainForm.cs	
@@ -11,7 +11,6 @@
 using System.Drawing;
 using System.Globalization;
 using System.IO;
-using System.Linq;
 using System.Windows.Forms;
 
 // Author Federico Blaseotto
@@ -86,7 +85,7 @@ private void CloseCurrentFile()
 #endif
         }
 
-        private bool canUpdate = false;
+        private bool canUpdate;
 
         private void CreateNewFile()
         {
@@ -341,7 +340,7 @@ private void openFileMenuItem_Click(object sender, EventArgs e)
                 {
                     OpenFile();
                 }
-                catch (Exception ex) when (ex is IOException || ex is UnauthorizedAccessException || ex is CFException)
+                catch (Exception ex) when (ex is IOException or UnauthorizedAccessException or CFException)
                 {
                     MessageBox.Show($"Cannot open file: {ex.Message}", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                 }
@@ -391,7 +390,7 @@ private void treeView1_MouseUp(object sender, MouseEventArgs e)
                     dgvUserDefinedProperties.DataSource = null;
                     dgvOLEProps.DataSource = null;
 
-                    if (stream.Name == "\u0005SummaryInformation" || stream.Name == "\u0005DocumentSummaryInformation")
+                    if (stream.Name is "\u0005SummaryInformation" or "\u0005DocumentSummaryInformation")
                     {
                         OLEPropertiesContainer c = stream.AsOLEPropertiesContainer();
 
@@ -402,7 +401,7 @@ private void treeView1_MouseUp(object sender, MouseEventArgs e)
 
                         foreach (OLEProperty p in c.Properties)
                         {
-                            if (p.Value is not byte[] && p.Value is IList list)
+                            if (p.Value is not byte[] and IList list)
                             {
                                 for (int h = 0; h < list.Count; h++)
                                 {
@@ -431,7 +430,7 @@ private void treeView1_MouseUp(object sender, MouseEventArgs e)
 
                             foreach (OLEProperty p in c.UserDefinedProperties.Properties)
                             {
-                                if (p.Value is not byte[] && p.Value is IList list)
+                                if (p.Value is not byte[] and IList list)
                                 {
                                     for (int h = 0; h < list.Count; h++)
                                     {
diff --git a/sources/Structured Storage Explorer/Utils.cs b/sources/Structured Storage Explorer/Utils.cs
index f61f0371..0a33f1fd 100644
--- a/sources/Structured Storage Explorer/Utils.cs	
+++ b/sources/Structured Storage Explorer/Utils.cs	
@@ -5,7 +5,7 @@
 
 namespace StructuredStorageExplorer
 {
-    class Utils
+    static class Utils
     {
         public static DialogResult InputBox(string title, string promptText, ref string value)
         {
@@ -30,7 +30,7 @@ public static DialogResult InputBox(string title, string promptText, ref string
             buttonCancel.SetBounds(309, 72, 75, 23);
 
             label.AutoSize = true;
-            textBox.Anchor = textBox.Anchor | AnchorStyles.Right;
+            textBox.Anchor |= AnchorStyles.Right;
             buttonOk.Anchor = AnchorStyles.Bottom | AnchorStyles.Right;
             buttonCancel.Anchor = AnchorStyles.Bottom | AnchorStyles.Right;
 
diff --git a/sources/Test/OpenMcdf.Benchmark/InMemory.cs b/sources/Test/OpenMcdf.Benchmark/InMemory.cs
index 73ca8fdd..c5de3a11 100644
--- a/sources/Test/OpenMcdf.Benchmark/InMemory.cs
+++ b/sources/Test/OpenMcdf.Benchmark/InMemory.cs
@@ -1,6 +1,5 @@
 using BenchmarkDotNet.Attributes;
 using BenchmarkDotNet.Order;
-using BenchmarkDotNet.Jobs;
 using System;
 using System.IO;
 
@@ -22,7 +21,7 @@ public class InMemory : IDisposable
 
         private byte[] _readBuffer;
 
-        private Stream _stream;
+        private MemoryStream _stream;
 
         [Params(Kb / 2, Kb, 4 * Kb, 128 * Kb, 256 * Kb, 512 * Kb, Kb * Kb)]
         public int BufferSize { get; set; }
diff --git a/sources/Test/OpenMcdf.Benchmark/Program.cs b/sources/Test/OpenMcdf.Benchmark/Program.cs
index a6459efa..34aa8734 100644
--- a/sources/Test/OpenMcdf.Benchmark/Program.cs
+++ b/sources/Test/OpenMcdf.Benchmark/Program.cs
@@ -2,11 +2,11 @@
 
 namespace OpenMcdf.Benchmark
 {
-    internal class Program
+    internal static class Program
     {
         private static void Main(string[] args)
         {
             BenchmarkSwitcher.FromAssembly(typeof(Program).Assembly).Run(args);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/sources/Test/OpenMcdf.Extensions.Test/CFSStreamExtensionsTest.cs b/sources/Test/OpenMcdf.Extensions.Test/CFSStreamExtensionsTest.cs
index a63931e7..d09a5182 100644
--- a/sources/Test/OpenMcdf.Extensions.Test/CFSStreamExtensionsTest.cs
+++ b/sources/Test/OpenMcdf.Extensions.Test/CFSStreamExtensionsTest.cs
@@ -1,7 +1,5 @@
 using Microsoft.VisualStudio.TestTools.UnitTesting;
-using System;
 using System.IO;
-using System.Linq;
 
 namespace OpenMcdf.Extensions.Test
 {
diff --git a/sources/Test/OpenMcdf.Extensions.Test/OLEPropertiesExtensionsTest.cs b/sources/Test/OpenMcdf.Extensions.Test/OLEPropertiesExtensionsTest.cs
index 98f73f97..5b72e304 100644
--- a/sources/Test/OpenMcdf.Extensions.Test/OLEPropertiesExtensionsTest.cs
+++ b/sources/Test/OpenMcdf.Extensions.Test/OLEPropertiesExtensionsTest.cs
@@ -545,7 +545,7 @@ public void Test_FIX_CRASH()
             bufferedStream.CopyTo(memoryStream);
 
             Assert.AreEqual(memoryStream.Length, cfStream.Size);
-          
+
         }
     }
 }
diff --git a/sources/Test/OpenMcdf.MemTest/Program.cs b/sources/Test/OpenMcdf.MemTest/Program.cs
index be7d44b5..0d8ff744 100644
--- a/sources/Test/OpenMcdf.MemTest/Program.cs
+++ b/sources/Test/OpenMcdf.MemTest/Program.cs
@@ -5,7 +5,7 @@
 
 namespace OpenMcdf.MemTest
 {
-    class Program
+    static class Program
     {
         static void Main(string[] args)
         {
@@ -130,7 +130,7 @@ private static void StressMemory()
             byte[] cmp = new byte[] { 0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7 };
 
             CompoundFile cf = new CompoundFile(CFSVersion.Ver_4, CFSConfiguration.Default);
-            CFStream st = cf.RootStorage.AddStream("MySuperLargeStream");
+            _ = cf.RootStorage.AddStream("MySuperLargeStream");
             cf.SaveAs("LARGE.cfs");
             cf.Close();
 
@@ -207,7 +207,7 @@ private static void DummyFile()
 
         private static void AddNodes(string depth, CFStorage cfs)
         {
-            Action<CFItem> va = delegate (CFItem target)
+            void va(CFItem target)
             {
                 string temp = target.Name + (target is CFStorage ? "" : " (" + target.Size + " bytes )");
 
@@ -222,7 +222,7 @@ private static void AddNodes(string depth, CFStorage cfs)
                     //Recursion into the storage
                     AddNodes(newDepth, (CFStorage)target);
                 }
-            };
+            }
 
             //Visit NON-recursively (first level only)
             cfs.VisitEntries(va, false);
diff --git a/sources/Test/OpenMcdf.PerfTest/Program.cs b/sources/Test/OpenMcdf.PerfTest/Program.cs
index 136659b5..f002f3a7 100644
--- a/sources/Test/OpenMcdf.PerfTest/Program.cs
+++ b/sources/Test/OpenMcdf.PerfTest/Program.cs
@@ -4,7 +4,7 @@
 
 namespace OpenMcdf.PerfTest
 {
-    class Program
+    static class Program
     {
         const int MAX_STREAM_COUNT = 5000;
         const string fileName = "PerfLoad.cfs";
@@ -19,7 +19,7 @@ static void Main(string[] args)
 
             CompoundFile cf = new CompoundFile(fileName);
             var stopwatch = Stopwatch.StartNew();
-            CFStream s = cf.RootStorage.GetStream("Test1");
+            _ = cf.RootStorage.GetStream("Test1");
             Console.WriteLine($"Elapsed: {stopwatch.Elapsed}");
             Console.Read();
         }
diff --git a/sources/Test/OpenMcdf.Test/CFStorageTest.cs b/sources/Test/OpenMcdf.Test/CFStorageTest.cs
index e382cdc8..861208e0 100644
--- a/sources/Test/OpenMcdf.Test/CFStorageTest.cs
+++ b/sources/Test/OpenMcdf.Test/CFStorageTest.cs
@@ -82,10 +82,10 @@ public void Test_VISIT_ENTRIES()
             using FileStream output = new("LogEntries.txt", FileMode.Create);
             using StreamWriter tw = new(output);
 
-            Action<CFItem> va = delegate (CFItem item)
+            void va(CFItem item)
             {
                 tw.WriteLine(item.Name);
-            };
+            }
 
             cf.RootStorage.VisitEntries(va, true);
         }
@@ -182,10 +182,10 @@ public void Test_VISIT_STORAGE()
 
             Console.SetOut(sw);
 
-            Action<CFItem> va = delegate (CFItem target)
+            void va(CFItem target)
             {
                 sw.WriteLine(target.Name);
-            };
+            }
 
             cf.RootStorage.VisitEntries(va, true);
         }
@@ -212,7 +212,7 @@ public void Test_DELETE_MINISTREAM_STREAM()
             using CompoundFile cf = new(FILENAME);
 
             CFStorage found = null;
-            Action<CFItem> action = delegate (CFItem item) { if (item.Name == "AnotherStorage") found = item as CFStorage; };
+            void action(CFItem item) { if (item.Name == "AnotherStorage") found = item as CFStorage; }
             cf.RootStorage.VisitEntries(action, true);
 
             Assert.IsNotNull(found);
@@ -229,11 +229,11 @@ public void Test_DELETE_STREAM()
             using CompoundFile cf = new(FILENAME);
 
             CFStorage found = null;
-            Action<CFItem> action = delegate (CFItem item)
+            void action(CFItem item)
             {
                 if (item.Name == "AnotherStorage")
                     found = item as CFStorage;
-            };
+            }
 
             cf.RootStorage.VisitEntries(action, true);
 
diff --git a/sources/Test/OpenMcdf.Test/CFStreamTest.cs b/sources/Test/OpenMcdf.Test/CFStreamTest.cs
index 0f4bfa4d..4f76a617 100644
--- a/sources/Test/OpenMcdf.Test/CFStreamTest.cs
+++ b/sources/Test/OpenMcdf.Test/CFStreamTest.cs
@@ -507,7 +507,7 @@ static IEnumerable<object[]> FuzzyBufferLengths
 
                 foreach (CFSVersion version in Enum.GetValues(typeof(CFSVersion)))
                 {
-                    for (int i = r.Next(1, 100); i < 1024 * 1024 * 70; i = i << 1)
+                    for (int i = r.Next(1, 100); i < 1024 * 1024 * 70; i <<= 1)
                     {
                         yield return new object[] { version, i + r.Next(0, 3) };
                     }
diff --git a/sources/Test/OpenMcdf.Test/CompoundFileTest.cs b/sources/Test/OpenMcdf.Test/CompoundFileTest.cs
index 00e28224..dd8963eb 100644
--- a/sources/Test/OpenMcdf.Test/CompoundFileTest.cs
+++ b/sources/Test/OpenMcdf.Test/CompoundFileTest.cs
@@ -363,7 +363,7 @@ public void Test_FUNCTIONAL_BEHAVIOUR()
 
             using (CompoundFile cfTest = new("6_Streams_Shrinked.cfs"))
             {
-                Action<CFItem> va = delegate (CFItem item)
+                static void va(CFItem item)
                 {
                     if (item.IsStream)
                     {
@@ -375,7 +375,7 @@ public void Test_FUNCTIONAL_BEHAVIOUR()
                         Assert.IsTrue(d.Length > 0);
                         Assert.AreEqual(ia.Size, d.Length);
                     }
-                };
+                }
 
                 cfTest.RootStorage.VisitEntries(va, true);
             }
@@ -776,7 +776,7 @@ public void Test_FIX_BUG_GH_14()
                 byte[] testBuffer = new byte[100];
                 byte t = 0x0A;
 
-                for (int streamId = 0; streamId<streamCount; ++streamId)
+                for (int streamId = 0; streamId < streamCount; ++streamId)
                 {
                     compoundFile.RootStorage.GetStorage(storageName).GetStream(streamName + streamId).Read(testBuffer, BUFFER_SIZE / 2, 100);
                     Assert.IsTrue(testBuffer.All(g => g == t));
@@ -1011,7 +1011,7 @@ public void Test_FIX_BUG_90_CompoundFile_Delete_Storages()
             // check if all storages can be found in to copied CompundFile
             foreach (var storageName in storageNames)
             {
-                Assert.IsTrue(cf.RootStorage.TryGetStorage(storageName, out var storage)); //<- we will see some missing storages here
+                Assert.IsTrue(cf.RootStorage.TryGetStorage(storageName, out _)); //<- we will see some missing storages here
             }
         }
 
@@ -1089,6 +1089,6 @@ public void Test_FIX_BUG_96_CompoundFile_SaveOverwrite()
             File.Delete(filename2);
         }
 
-       
+
     }
 }
diff --git a/sources/Test/OpenMcdf.Test/RBTreeTest.cs b/sources/Test/OpenMcdf.Test/RBTreeTest.cs
index 77f48476..c88bc143 100644
--- a/sources/Test/OpenMcdf.Test/RBTreeTest.cs
+++ b/sources/Test/OpenMcdf.Test/RBTreeTest.cs
@@ -1,6 +1,5 @@
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using RedBlackTree;
-using System;
 using System.Collections.Generic;
 
 namespace OpenMcdf.Test
@@ -43,12 +42,12 @@ public RBTreeTest()
         //
         #endregion
 
-        internal IList<IDirectoryEntry> GetDirectoryRepository(int count)
+        internal static IList<IDirectoryEntry> GetDirectoryRepository(int count)
         {
             List<IDirectoryEntry> repo = new List<IDirectoryEntry>();
             for (int i = 0; i < count; i++)
             {
-                IDirectoryEntry de = DirectoryEntry.New(i.ToString(), StgType.StgInvalid, repo);
+                _ = DirectoryEntry.New(i.ToString(), StgType.StgInvalid, repo);
             }
 
             return repo;
@@ -85,9 +84,9 @@ public void Test_RBTREE_DELETE()
                 rbTree.Insert(item);
             }
 
-            rbTree.Delete(DirectoryEntry.Mock("5", StgType.StgInvalid), out IRBNode n);
-            rbTree.Delete(DirectoryEntry.Mock("24", StgType.StgInvalid), out n);
-            rbTree.Delete(DirectoryEntry.Mock("7", StgType.StgInvalid), out n);
+            rbTree.Delete(DirectoryEntry.Mock("5", StgType.StgInvalid), out _);
+            rbTree.Delete(DirectoryEntry.Mock("24", StgType.StgInvalid), out _);
+            rbTree.Delete(DirectoryEntry.Mock("7", StgType.StgInvalid), out _);
 
             //    CFItem c;
             //    bool s = rbTree.TryLookup(new CFMock("7", StgType.StgStream), out c);
@@ -120,7 +119,7 @@ private static Color NodeColor(IRBNode n)
 
         private static void VerifyProperty1(IRBNode n)
         {
-            Assert.IsTrue(NodeColor(n) == Color.RED || NodeColor(n) == Color.BLACK);
+            Assert.IsTrue(NodeColor(n) is Color.RED or Color.BLACK);
 
             if (n == null) return;
             VerifyProperty1(n.Left);
diff --git a/sources/Test/OpenMcdf.Test/SectorCollectionTest.cs b/sources/Test/OpenMcdf.Test/SectorCollectionTest.cs
index 05d9bba9..ab5f32a2 100644
--- a/sources/Test/OpenMcdf.Test/SectorCollectionTest.cs
+++ b/sources/Test/OpenMcdf.Test/SectorCollectionTest.cs
@@ -1,7 +1,5 @@
 using Microsoft.VisualStudio.TestTools.UnitTesting;
-using System;
 using System.Collections.Generic;
-using System.Linq;
 
 namespace OpenMcdf.Test
 {