The Jail spell is used for punishment.
It sends the user to the Jail location, gives them a tag with a reason why they were sent. It is a much weaker form of the more permanent Ban Spell Few people have this ability as it is very powerful.
Ann. 1967 - [2011-08-09 06:30:00 - Stage 10]
Clearing some things about Jail Time and releases
The only right way to get out of jail is by being released by those that have this ability. When someone is sent to jail, the sentence time refers to a MINIMUM TIME that person will stay there. After that period, that person can be released from jail only by those with the right ability to do that, WHEN and IF they wish so. the unban ability is a personal ability and as such is used at the owners discretion. However there are other ways that can be used at your own risk, to get out of jail when time is up, or if you dare sooner, otherwise what would be the point of having fugitives features and such things :). Fugitives will obviously find it a lot harder to ever clear their name, integrate back, receive public roles, etc, so don't joke about choosing that path, even if a "criminal path" is now technically supported by the interface.