Request for Comments: xxxx S. B. Palmer Category: Informational July 2001 A "geo" URN Namespace Status of this Memo This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2001). All Rights Reserved. Abstract Identifiers for geospatial locations are in wide use around the world, and yet there is no standardized scheme allowing one to refer to them on the World Wide Web. This is a specification for a URN namespace to do just that. 1. Introduction This document proposes the "geo" namespace, which enables people to refer to geographical locations based upon a latitude and a longitude. The namespace specification is for a formal namespace. 2. Specification Template Namespace ID: "geo" requested Palmer Informational [Page 1] RFC xxxx A "pts" URN Namespace July 2001 Registration Information: Registration version number: 1 Registration date: 2001-09-09 Declared registrant of the namespace: Name: Sean B. Palmer email address: Declaration of syntactic structure: The syntactic definition of these URNs in standard ABNF [RFC-2234] is:- urn = "urn:" nid ":" location nid = "geo" ; requested location = hms / pnt hms = hmslat "," hmslong [ "," height ] hmslat = hmslatc lat hmslatc = ( d89 ":" [ d60 ":" d60 ] ) / "90:00" [ ":00" ] hmslong = hmslongc long hmslongc = ( d179 ":" [ d60 ":" d60 ] ) / "180:00" [ ":00" ] pnt = pntlat "," pntlong [ "," height ] pntlat = pntlatc lat pntlatc = ( d89 [ "." *d dx0 ] ) / "90" pntlong = pntlongc long pntlongc = ( d179 [ "." *d dx0 ] ) / "180" lat = "N" / "S" long = "E" / "W" height = [ "-" ] dx0 *d [ "." *d dx0 ] ( "m" / "ft" ) d179 = dx0 / ( dx0 d ) / ( "1" d7 d ) ; 0-170 d89 = dx0 / ( d7 d ) / ( "8" d ) ; 0-89 d60 = ( d5 d ) / "60" ; 00-60 d = d7 / "8" / "9" ; 0-9 d7 = d6 / "7" ; 0-7 d6 = d5 / "6" ; 0-6 d5 = %x30-35 ; 0-5 dx0 = %x31-39 ; 1-9 Examples of syntactically valid URNs under this scheme include:- urn:geo:55:58:30N,178:35:53E urn:geo:55.039378S,178.01897E urn:geo:15:58:30N,17:35:17E,25m urn:geo:15:58:30N,17:35:17E,-53.87ft urn:geo:0,0,0m Relevant ancillary documentation: All URNs defined herein conform to [RFC 2141]. Palmer Informational [Page 1] RFC xxxx A "pts" URN Namespace July 2001 [RFC 2141] Moats, R. "URN Syntax", RFC 2141, , May 1997. [RFC-2234] D. Crocker "Augmented BNF for Syntax Specifications: ABNF", , November 1997. Identifier uniqueness considerations: Each coordinate location is a unique point in 3 dimensional space. Uniqueness is guaranteed by the syntax of latitudes and longitudes, which has been developed over many years. Identifier persistence considerations: Since latitudes and longitudes are widely agreed upon global identifiers, there can be no ambiguity as to what location each identifier represents. Process of identifier assignment: Assignment of URNs using this scheme is closed by the syntax of this specification. The equator is taken to be 0 latitude, and the Greenwich meridian is taken to be 0 longitude. The height 0 is given by sea level. Identifiers without a height component are taken to identify the point on the surface of the earth at that location. Process for identifier resolution: None specified. Rules for Lexical Equivalence: Certain latitudes and longitudes are equivalent, and the same with heights, to allow for different units of measure. These URNs are also case insensitive. For example the following are all equivalent:- urn:geo:0n,0W,0m urn:GEO:0:00:00S,0:00:00e,-0M URN:geo:0S,0E,0ft because the values are the same. For human readability, it is is recommended (but by no means required) that the ABNF for the scheme be treated as case sensitive, and that the "N" and "E" are defaulted to. Hence, the recommended form for the URNs above is:- urn:geo:0N,0E,0m Conformance with URN Syntax: No special considerations. Processors of these URNs must follow the conventions in [RFC 2141], notably Section 5, "Lexical Equivalence in URNs". Validation mechanism: None specified. Scope: Global. These URNs may be referred to by anyone worldwide, for use in their own applications. The use of these URNs encouraged. Palmer Informational [Page 3]