When I do /help /join, I'm given two choices.
The first choice displays the standard IRC command, which doesn't have the switches.
However, the second choice, which is mIRC's command, shows the following
/join [-inx] <#channel>
This is a standard IRC command for joining a channel.
The -i switch makes you join the channel to which you were last invited.
The -n and -x switches minimize/maximize the channel window when you join it.
