If you're also an IRC user you are familiar with the concept of changing your nickname in the middle of a conversation, and you probably noted that this is not permitted in our IRC emulation of psyced.
Changing nickname on IRC has the negative side effect of changing your identity, that's why we had to forbid that, but it also serves the positive purposes of giving you an extra means of expression within a group conversation to either advertise another variant of you, or to simply play around with the virtual concept of being someone else.
In PSYC we have separated this gimmickish use from the identity concept and introduced temporary nicknames which are only visible in a particular place where masquerading has been enabled.
Once in such a room you can use the /nick command to impersonate other names. See the command documentation for technical details.
Sadly, the technology that inspired this is the one that needs to be excluded. IRC clients cannot understand local nickname changes, so masquerading is not visible when using IRC clients.