Reclaiming a zombie nick/session in IRC

Sometimes, it happens that one’s IRC session isn’t terminated properly (i.e. when the IRC client crashes). When logging in again, you may not be able to login with your real nickname (‘mynick’) and have to temporarily use another nickname (let’s say ‘fallbacknick’). The easiest solution to this problem is declaring the zombie session as a ghost with the help of nickserv. You can do this with an IRC nickserv command similar to this one:

/msg NickServ GHOST mynick mypassword

Afterwards, you can reclaim your original nickname again:

/nick mynick

The complete help page about this nickserv command:

***** NickServ Help *****
Help for GHOST:

GHOST disconnects an old user session, or somebody
attempting to use your nickname without authorization.

If you are logged in to the nick’s account, you need
not specify a password, otherwise you have to.

Syntax: GHOST <nick> [password]

/msg NickServ GHOST foo bar
***** End of Help *****