cryptographically verified messages
.TP
~x \fIEXPR\fP
-messages which contain \fIEXPR\fP in the \(lqReferences\(rq field
+messages which contain \fIEXPR\fP in the \(lqReferences\(rq or \(lqIn-Reply-To\(rq field
.TP
~X \fIMIN\fP-\fIMAX\fP
messages with MIN - MAX attachments
.PP
In the above, \fIEXPR\fP is a regular expression.
.PP
-With the \fB~m\fP, \fB~n\fP, \fB~X\fP, and \fB~z\fP operators, you can also
+With the \fB~d\fP, \fB~m\fP, \fB~n\fP, \fB~r\fP, \fB~X\fP, and \fB~z\fP operators, you can also
specify ranges in the forms \fB<\fP\fIMAX\fP, \fB>\fP\fIMIN\fP,
\fIMIN\fP\fB-\fP, and \fB-\fP\fIMAX\fP.
+.PP
+With the \fB~z\fP operator, the suffixes \(lqK\(rq and \(lqM\(rq are allowed to specify
+kilobyte and megabyte respectively.
.SS Matching dates
.PP
The \fB~d\fP and \fB~r\fP operators are used to match date ranges,