.I field
switch causes
.B sortm
-to sort messages
-by the specified text field. If this field is \*(lqsubject\*(rq, any
-leading "re:" is stripped off. In any case, all characters except
+to sort messages by the specified text field. All characters except
letters and numbers are stripped and the resulting strings are sorted
-datefield\-major, textfield\-minor, using a case insensitive comparison.
+datefield\-major, textfield\-minor, using a case insensitive
+comparison. If this field is \*(lqsubject\*(rq, any leading "re:" is
+stripped off.
.PP
With
.B \-textfield
.B \-limit
.I days
is specified, messages
-with similar textfields that are dated within `days' of each other
+with the same textfields that are dated within `days' of each other
appear together. Specifying
.B \-nolimit
makes the limit infinity.
.IR 0 ,
the sort is instead made textfield\-major, date\-minor.
.PP
-For example, to order a folder by date-major, subject-minor, use:
+For example, to order a folder by date-major, grouping messages with
+the same subject on the same date together, use:
.PP
.RS 5
sortm -textfield subject +folder
If a folder is given, it will become the current folder. If the current
message is moved,
.B sortm
- will preserve its status as current.
+will preserve its status as current.
.SH HISTORY
Timezones used to be ignored when comparing dates: they aren't any more.