(Matrix and Scalar Modes, Kinds of Declarations): Mention square

matrix mode.

man/calc.texi

@@ -12817,7 +12817,9 @@ If you press @kbd{m v} with a numeric prefix argument @var{n}, you
 get a special ``dimensioned'' Matrix mode in which matrices of
 unknown size are assumed to be @var{n}x@var{n} square matrices.
 Then, the function call @samp{idn(1)} will expand into an actual
-matrix rather than representing a ``generic'' matrix.
+matrix rather than representing a ``generic'' matrix.  Simply typing
+@kbd{C-u m v} will get you a square Matrix mode, in which matrices of
+unknown size are assumed to be square matrices of unspecified size.
 @cindex Declaring scalar variables
 Of course these modes are approximations to the true state of
@@ -13205,6 +13207,8 @@ The value is not a vector.
 The value is a vector.
 @item matrix
 The value is a matrix (a rectangular vector of vectors).
+@item sqmatrix
+The value is a square matrix.
 @end table
 These type symbols can be combined with the other type symbols
@@ -15978,7 +15982,8 @@ Command is @kbd{m p}.
 @item
 Matrix/Scalar mode.  Default value is @mathit{-1}.  Value is 0 for Scalar
-mode, @mathit{-2} for Matrix mode, or @var{N} for 
+mode, @mathit{-2} for Matrix mode, @mathit{-3} for square Matrix mode,
+or @var{N} for  
 @texline @math{N\times N}
 @infoline @var{N}x@var{N} 
 Matrix mode.  Command is @kbd{m v}.
@@ -16056,7 +16061,10 @@ Symbolic mode (@kbd{m s}; @pxref{Symbolic Mode}).
 Matrix mode (@kbd{m v}; @pxref{Matrix Mode}).
 @item Matrix@var{n}
-Dimensioned Matrix mode (@kbd{C-u @var{n} m v}).
+Dimensioned Matrix mode (@kbd{C-u @var{n} m v}; @pxref{Matrix Mode}).
+
+@item SqMatrix
+Square Matrix mode (@kbd{C-u m v}; @pxref{Matrix Mode}).
 @item Scalar
 Scalar mode (@kbd{m v}; @pxref{Matrix Mode}).