diff --git a/src/csv/mod.rs b/src/csv/mod.rs
index 55ac8c0..2fa613e 100644
--- a/src/csv/mod.rs
+++ b/src/csv/mod.rs
@@ -59,32 +59,52 @@ pub enum Error {
     UnequalRowCount(usize, usize),
 }
 
+/// A position inside a table
 #[derive(Clone, Copy, Debug, Serialize)]
 pub struct Position {
+    /// row number, starting with zero
     pub row: usize,
+    /// column number, starting with zero
     pub col: usize,
 }
 
 #[derive(Debug, Serialize, Clone)]
+/// Difference of a table entry
 pub enum DiffType {
+    /// Both entries were strings, but had different contents
     UnequalStrings {
+        /// nominal string
         nominal: String,
+        /// actual string
         actual: String,
+        /// position
         position: Position,
     },
+    /// Both entries were [`Quantity`]s but exceeded tolerances
     OutOfTolerance {
+        /// nominal
         nominal: Quantity,
+        /// actual
         actual: Quantity,
+        /// compare mode that was exceeded
         mode: Mode,
+        /// position in table
         position: Position,
     },
+    /// both fields had different value types
     DifferentValueTypes {
+        /// nominal
         nominal: Value,
+        /// actual
         actual: Value,
+        /// position
         position: Position,
     },
+    /// Both fields were headers but with different contents
     UnequalHeader {
+        /// nominal
         nominal: String,
+        /// actual
         actual: String,
     },
 }
diff --git a/src/properties.rs b/src/properties.rs
index 1ca0e57..870b22f 100644
--- a/src/properties.rs
+++ b/src/properties.rs
@@ -103,13 +103,14 @@ fn file_modification_time_out_of_tolerance(
                     result.is_error = true;
                 }
             } else {
-                let msg = format!("Could not calculate duration between modification timestamps");
+                let msg =
+                    "Could not calculate duration between modification timestamps".to_string();
                 error!("{}", &msg);
                 result.push_detail(DiffDetail::Error(msg));
                 result.is_error = true;
             }
         } else {
-            let msg = format!("Could not read file modification timestamps");
+            let msg = "Could not read file modification timestamps".to_string();
             error!("{}", &msg);
             result.push_detail(DiffDetail::Error(msg));
             result.is_error = true;