to just after the first non-listed track before it, or to the head if there is
no such track.
.TP
+.B nop
+Do nothing. Used by
+.BR disobedience (1)
+as a keepalive measure.
+.TP
.B part \fITRACK\fR \fICONTEXT\fI \fIPART\fR
Get a track name part. Returns an empty string if a name part cannot be
constructed.