Types of CDP in RFC2459

["Eissa, Mohamed" <mohamed.eissa@xxxxxxxxx>]

Hi all,
In RFC2459 (Internet X.509 Public Key Infrastructure Certificate and CRL
Profile)  http://www.ietf.org/rfc/rfc2459.txt
4.2.1.14 CRL Distribution Points 
	The CRL distribution points extension identifies how CRL information
is obtained. The extension SHOULD be non-critical, but this profile
recommends support for this extension by CAs and applications. Further
discussion of CRL management is contained in section 5. 
	If the cRLDistributionPoints extension contains a
DistributionPointName of type URI, the following semantics MUST be assumed:
the URI is a pointer to the current CRL for ...


Can someone please help me to list what are the other possible types for CDP
if it is not a URI?

Mohamed Eissa
Intel of Canada