Normally, if a command is part of a series of commands, an undocumented switch usually means the same thing as what it meant for the previous command on the same help page. And that would be the /drawdot command that says -i is inverse. There is already a -p switch that lets you italicize (or use other control codes) in the text, so I think -i should be inverse.

Invision Support
#Invision on