+\fBb <regexp>\fR (body)
+
+selects mails whose body matches the regexp. Evaluating such a
+condition requires to read the full mail from the original mboxes,
+which can be slow. To speed things up, all the header conditions are
+checked first.
+.TP
+\fB8h\fR, \fB24h\fR, \fB48h\fR, \fBweek\fR, \fBmonth\fR, \fBtrimester\fR, and \fByear\fR
+
+select mails received during the last 8, 24, 48, 7 * 24 hours, 31 *
+24 hours, 92 * 24 hours, and 365 * 24 hours respectively.