diff --git a/docs/columns.md b/docs/columns.md
index bd89ef162..bbbff3984 100644
--- a/docs/columns.md
+++ b/docs/columns.md
@@ -206,6 +206,7 @@ Command       Operation
 ` z(`         expand _current_ column to a specific depth (prompt for input)
 `gz(`         expand _all visible_ columns to a specific depth (prompt for input)
 `  )`         contract (unexpand) the current column
+` zM`         expand _current_ column row-wise within that column
 
 The following demo shows `(` commands applied to this data:
 
diff --git a/docs/rows.md b/docs/rows.md
index 31a60a286..008b04a3b 100644
--- a/docs/rows.md
+++ b/docs/rows.md
@@ -115,8 +115,10 @@ Command(s)         Operation
 
 Command(s)         Operation
 -----------------  -------------
- `[`  `]`          sorts ascending/descending by **current** column
-`g[` `g]`          sorts ascending/descending by **all key** columns
+ `[`  `]`          sorts ascending/descending by **current** column; replace any existing sort criteria
+`g[` `g]`          sorts ascending/descending by **all key** columns; replace any existing sort criteria
+`z[` `z]`          sorts ascending/descending by **current** column; add to existing sort criteria
+`gz[` `gz]`        sorts ascending/descending by **all key** column; add to existing sort criteria
 
 ###### How to sort a numerical column from highest number to lowest:
 
@@ -133,6 +135,11 @@ Command(s)         Operation
 1. Press `!` on those columns to designate them as key columns.
 2. Press `g[` or `g]` to sort.
 
+**or**
+
+1. Sort the first column with `[` or `]`.
+2. Sort the next column with `z[` or `z]` to add sorting to the existing criteria.
+
 ###### How to increase row height
 
 Press `v` on any **TableSheet** to toggle multi-line rows. This dynamically lengthens rows so that the full content of the column is visible.