Comparable and replaceable fax numbers

Hi,

On my servers I've redefined facsimileTelephoneNumber as a telephoneNumber:

attributetype ( 2.5.4.23 NAME ( 'facsimileTelephoneNumber' 'fax' ) DESC 'RFC2256: Facsimile (Fax) Telephone Number' SUP telephoneNumber )

This requires reimporting the database since the normalisation changes, but it adds comparison rules to fax numbers (allowing comparison and replacement of them):

Before: ldapcompare -x uid=person1234,dc=example,dc=com facsimiletelephonenumber::KzEoNTU1KS01NTUtNTU1NQ== Compare Result: Inappropriate matching (18) Additional info: inappropriate matching request UNDEFINED

After: ldapcompare -x uid=person1234,dc=example,dc=com facsimiletelephonenumber::KzEoNTU1KS01NTUtNTU1NQ== TRUE

Is there any reason to follow the RFC in this case? The RFC itself doesn't make a good argument for or against fax numbers having a separate syntax with no matching rules.