This document specifies the URI (Uniform Resource Identifier) scheme "tel". The "tel" URI describes resources identified by telephone numbers. This document obsoletes RFC 2806.
RFC 3966 introduction
This document defines the URI scheme "tel", which describes resources identified by telephone numbers. A telephone number is a string of decimal digits that uniquely indicates the network termination point. The number contains the information necessary to route the call to this point. (This definition is derived from [E.164] but encompasses both public and private numbers.)
Click here to download RFC 3966: TXT formatPDF format (coming soon)