DEF:<vname>=<rrdfile>:<ds-name>:<CF>[:step=<step>][:start=<time>]​[:end=<time>]​[:reduce=<CF>]​[:daemon=<address>]

[output] \&\fBDEF:\fR\fvname\fR=\frrdfile\fR:\fds\-name\fR:\fCF\fR[:step=\fstep\fR][:start=\ftime\fR]\:[:end=\ftime\fR]\:[:reduce=\f\fR\f(BICF\fR\fI\fR]\:[:daemon=\faddress\fR]