IETF RFC 2609 PDF

The "service:" URL scheme name is used to define URLs (called "service: URLs" in this document) that are primarily intended to be used by the Service Location Protocol in order to distribute service access information. These schemes provide an extensible framework for client-based network software to obtain configuration information required to make use of network services. When registering a service: URL, the URL is accompanied by a set of well-defined attributes which define the service. These attributes convey configuration information to client software, or service characteristics meaningful to end users.

This document describes a formal procedure for defining and standardizing new service types and attributes for use with the "service:" scheme. The formal descriptions of service types and attributes are templates that are human and machine understandable. They SHOULD be used by administrative tools to parse service registration information and by client applications to provide localized translations of service attribute strings.