asterisk users - Nov 2010 - Contradiction in GROUP() function

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

On 24 November 2010 10:12, Steve Davies <davies147 at gmail.com>
wrote:
> 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?
I suspect from further reading the code that this might just be a
misleading error message.

Regards
Steve