[asterisk-users] Contradiction in GROUP() function

[Steve Davies]

I am confused. In Asterisk 1.2 and 1.4, in the code there is an error:
"Setting a group requires an argument (group name)"

But the syntax is shown as: "Syntax: GROUP([category])"

The [category] square brackets indicate to me an "optional" parameter,
which contradicts the error.

Verison 1.6 is non-committal in its definition, but I always assumed
that an empty string was still a valid category-name, so GROUP()=123
is as valid as GROUP(X)=123.

Could this be clarified?

Many thanks,
Steve