matchingRuleUse / extensibleMatch

Two questions:
 
1) In [Models], MatchingRuleUseDescription.APPLIES says: "provides a
list of attribute types the matching rule applies to". Does this include
or exclude subtypes?
 
2) In [Protocol], SearchRequest.filter.extensibleMatch says: "If the
type field is absent and the matchingRule is present, the matchValue is
compared against all attributes in an entry which support that
matchingRule.". Does this mean "as determined by any matchingRuleUse for
that mathing rule", or "as determined by any matchingRuleUse, or the
EQUALITY, ORDERING, or SUBSTR rules of the attribute"?
 
Whatever the answers are to these, I don't find it obvious by reading
the text.
 
Jim