A B C D E F G H I J K L M N O P Q R S T U V W X Y Z ?

x

1. verb⁰ Abbreviation for the 'exits' command. When newbies start using this in earnest, it's one of the signs they're hooked!

2. preposition Abbreviation for 'except', an excluding preposition.

3. preposition The universal preposition used in BL. Any word will do, and although x isn't actually defined as a preposition, it's traditionally the one to use.