XMI13 — Clarify Management of Tags in MOF Models

Section 4.7.2 states that "enforceMin(Max)imumMultiplicity" should be
attached to the MOF metamodel. This does not seem appropriate: the required
validation is most likely to vary by import context, not be static for
every application of the metamodel. The potential alternative of having a
set of 'validation options' that can be specified as part of the import
operation is that these options also affect the schema generated and need
to be available to tools.
The submitters have in mind use of separately packaged tag sets separate
from the metamodel: these ideas should be explained.
The specification should also explain a simple way for tools to know
exactly what are the options used in an XMI document.

Clarify by adding text