ID
N In Lacewing Blue Server, this returns the currently selected channel's ID, which is 0 to 65534, inclusive.
If no channel is selected, this expression will return -1.
Internally, both Relay and Blue use IDs for their channels, much like peers, and only send the channel names in channel join messages. Only Blue exposes the use of channel IDs directly.
For a performance boost, you should prefer using IDs over names, for reasons discussed in the Tips topic.
Channel IDs are assigned on creation request, on a lowest available basis, and never changed, so if three channels are created, and the second channel to be created is closed, there will be 2 channels but with IDs 0 and 2, not 0 and 1.