I’ve seen it take arguments, and apparently there’s a starred version, but I can’t find any documentation because it is ungooglable!
There is no official name for it (at least I don't know of any) and it would be difficult to give it a single short name as the purpose of this command is more or less
Now turn this into a short word please :-)
The full syntax in standard LaTeX is
This is what all environments etc of standard LaTeX use when they make use of this command. The actual code that the command runs depends on the situation, so in a
An introduction such as ltshort will cover this command in detail, along with other ungooglable terms.