questions about attribute declarations

Questions about attribute declarations I'd like to see discussed while
the voting booth is still open:

*  Should XML retain SGML's prohibition on multiple attribute-list
declarations for the same element (11.3.1) or on multiple declarations
for the same attribute (11.3.2)?

* Should XML change the set of types available for attributes?
E.g. by suppressing NAME(S), NUMBER(S), NMTOKEN(S), NUTOKEN(S) and
adding constraints in the form of regular expressions, ISO dates,
language-code, external-id, typed IDREF, ... (7.9.4, 11.3.3)

* Should XML remove SGML's prohibition on multiple ID or NOTATION
attributes on the same element (11.3.3)?

* Should XML allow more than one enumerated type (name-group declared
value) to contain the same possible value (11.3.3)?

(Since XML seems unlikely to support SHORTTAG, this restriction seems
pointless in XML.  It does affect the translation of XML DTDs into

* Should XML define new specific methods of inferring values for
attributes with no attribute-value specifications (11.3.4)?  E.g.
INHERITED, to signify that the value is taken from the attribute of the
same name (and type) on the smallest enclosing element with such an

(This is the method normally used for setting the default of language
attributes, among others; currently it has no SGML keyword.)

* When given an incomplete DTD, should XML parsers assume all attributes
are implicity declared CDATA, or should some attribute names cause other
assumptions (e.g. attributes with the same name as some type of declared
value might be assumed to have that declared value)?