X500Principal(String) currently understands a fixed set of
attribute type keywords (it cannot be extended).

Unfortunately, this is a problem when X500Principal is used to parse
DNs (ex: generated by other toolkits or protocols) that contain keywords outside of this fixed set.

Also, new standard attribute type keywords can be registered with IANA
(http://www.iana.org). We should provide a method to allow our implementation
to recognize new keywords (and this is what the successor to RFC 2253 is
recommending; see section 2.3 of http://ietf.org/internet-drafts/draft-ietf-ldapbis-dn-15.txt)

Furthermore, the "SN" and "GN" abbreviations are more
commonly used in DNs and should be accepted in addition to the "SURNAME"
and "GIVENNAME" keywords in the fixed set. For example, see the examples
in RFC 2253 which use "SN". However, we cannot add new keywords to the
fixed set without breaking compatibility.

###@###.### 10/20/04 16:54 GMT
###@###.### 2005-1-06 18:12:23 GMT