http://www.rfc-editor.org/rfc/rfc3510.txt
RFC 3510: Internet Printing Protocol/1.1: IPP URL Scheme, R. Herriot, I. McDonald2003-04-01T23:00:00-00:00This memo defines the "ipp" URL (Uniform Resource Locator) scheme. This memo updates IPP/1.1: Encoding and Transport (RFC 2910), by expanding and clarifying Section 5, "IPP URL Scheme", of RFC 2910. An "ipp" URL is used to specify the network location of a print service that supports the IPP Protocol (RFC 2910), or of a network resource (for example, a print job) managed by such a print service. [STANDARDS-TRACK]