Don't understand Tag Groupings as described in user guide

[adama]

See:
http://sparxsystems.com/enterprise_architect_user_guide/13.0/modeling_tools/define_tag_groupings.html

"You can apply the same solution, using three tag grouping special attributes in the Metaclass element extended by the Stereotype element in which the tags are defined as attributes."... the Technology Developer defined the special attributes in the Activity Metaclass element"

Trying to parse this vague instruction:

1) "...using three tag grouping special attributes in the Metaclass element ..."
So, you add each of the special attributes to the metaclass (e.g. Activity). So what then?  In the example, the values for _tagGroups is "Base Element,Activity,Task,AdHoc,Loop,Sub-Process,Callable Element,Execution,Other". But, an attribute does not have values; it has only initial value. What does this mean?  I tried adding tagged values on the attribute, tagged values on the element, a tagged value on element that has the comma-separated string as the value...with no success.  Same question about _tagGroupings and _tagGroupStates.

2) "...extended by the Stereotype element in which the tags are defined as attributes."
What tags? I guess that means these attributes will be expressed as tags in class instances.
Anyway, from this instruction, I suppose one should create an attribute for each item in _tagGroupings.

Totally confused by this instruction. Any help by example, perhaps?

[Glassboy]

This is much easier to understand if you use the helper to do it rather than hand coding.

[adama]

Thanks Glassboy. Where is the helper? Oh, it's the "Add Stereotype". Works for me. Thanks again.

[adama]

BTW, my problem might have been that the _tag attributes in the metaclass, as well as the attributes in the stereotype, were PRIVATE. Making them public seemed the proper approach.