Server protocol:User ID

When you enable SID in the PROTOCTL command you enable support for Server and User ID's. UID's consist of alphanumerical characters and can (theoretically) be used at any place where you use a nick name. The first 3 characters identify the SID of the server where the user is on (this is part of the UID) and thus a UID will always start with a digit.

The benefit of using UID's is that it really uniquely identifies a user regardless of the current nick name. This allows us to solve some long-standing problems where nick collisions and race conditions that cause desynchs such as 'ghosts' in a channel.

Example: :One NOTICE Two :Hi there

Can become: :001AAAAAA NOTICE 002AAAAAA :Hi there

As you can see, it doesn't necessarily shorten the length, that isn't the purpose of UID. The benefit of UID is the uniqueness described earlier.

See also:
 * Server ID