/usr/share/irssi/help/unload is in irssi 0.8.17-1+deb8u5.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | %9Syntax:%9
UNLOAD %|<module> [<submodule>]
%9Parameters:%9
The name of the module to unload.
%9Description:%9
Removes a module from the memory.
%9Examples:%9
/UNLOAD fish
%9See also:%9 LOAD, SCRIPT
|