Add dependency over a package providing the /usr/bin/cal command, which is needed to enable the "cal" plugin for rbot. If the USE flag is disabled the plugin is also disabled by default.

Packages describing “cal” as local USE flag

Package “cal” Flag Description
net-irc/rbot Add dependency over a package providing the /usr/bin/cal command, which is needed to enable the "cal" plugin for rbot. If the USE flag is disabled the plugin is also disabled by default.
app-text/stardict Enable calendar support using cal program

All packages providing a “cal” USE flag (1)