eduPerson schema and SUBSTR matching rules

[macrotex]

The LDAP eduPerson Object Class Specification defines the eduPerson attributes and includes the EQUALITY matching rule but not the SUBSTR matching rule.

However, at the eduPerson LDIF Files page there is a link to two LDIF files (in a zip file). One of the LDIF files has the schema with SUBSTR matching rules while the other does not.

Why aren't the SUBSTR matching rules included on the main page describing the Object Class Specifications?