IDs - Optional attributes (E)

Hi David, all,

> *E)*
> Value of optional id attributes is questionable
> *Proposed change:*
> Depending on the resolution of D above, make all ids required.
> Complementary kill ids where they seem to be optional.

To which comment this major change would corresponds too?

Comment 121 (not listed in your enumeration) proposes this change for <segment> id only.
In addition to <segment>, id is currently optional in: <file>, <group>, <ignorable> and <note>.

I think you also forgot to list the arguments supporting the statement "Value of optional id attributes is questionable". Could you
elaborate and give examples?

-yves