Namespaces and URNs

Robin Cover robin at ACADCOMP.SIL.ORG
Wed Aug 5 17:12:59 BST 1998

Eliot Kimber wrote:

> Note that with TC1 to ISO 8879 (SGML) that domain names are recognized as
> registered owner names (equivalent to URN namespace IDs), so if you already
> have a domain name, you can immediately construct FPIs that are guaranteed
> to be universally unique. They will be yours to manage as long as you own
> the domain name.

Reference:  (for example)

and see sections:

  K.4.6 Internet domain names in public identifiers
  K.3.8.1 Universal Resource Names

Partial extract:

K.4.6 Internet domain names in public identifiers

[80] owner identifier =

ISO owner identifier |

registered owner identifier |

unregistered owner identifier |

internet domain name owner identifier

[83.1] internet domain name owner identifier =

"+//IDN ", minimum data

where the minimum data must begin with an internet domain name.

Note 25: The string "IDN" is treated as an ISO/IEC 9070
"registeredowner prefix". Any sub-domain names could be expressed as
owner name components. For example, the internet domain name in
"" could occur in an FPI as:


or as: 


Note 26: When constructing a public text owner identifier using an
internet domain name, users may wish to consider the name's potential
lifespan and that of the objects to be identified by public
identifiers that use it.

Semicolon, exclamation point, asterisk, number sign, commercial at
sign, dollar sign, underscore, and percent sign are members of the
abstract character class "special", which is usable in minimum data.


K.3.8.1 Universal Resource Names

[198.1] urn feature =

ps+, "URN", ps+, ("NO"|"YES")


URN YES means public identifiers are interpreted according to the

  applicable Internet Engineering Task Force RFC2141 governing

  Universal Resource Names.

If both URN and FORMAL are YES, public identifiers are interpreted
either as formal public identifiers or as URNs.


Robin Cover                    Email: robin at
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