In this approach[4], URCs are collections of attribute/value pairs, much like the headers on electronic mail and Usenet news messages. Currently there are no attributes which are required to be present. The following minimal set of attributes is being used experimentally:
In addition, HTTP headers may also be included in the URC, e.g.
In the whois++ scenario, a sample URC would look something like this:
Author: Richard Coleman <zsh@math.gatech.edu>
Title: The Z Shell
URN:dns:shells.unix.computing.subject:zsh
URL:ftp://ftp.math.gatech.edu/pub/zsh
URL:ftp://ftp.sterling.com/zsh
URL:ftp://ftp.cenatls.cena.dgac.fr/pub/shells/zsh
URL:ftp://mrrl.lut.ac.uk/zsh
Abstract: the Z-shell, a command interpreter for many UNIX systems
which is freely available to anyone with FTP access. Zsh is more
powerful than every other common shell (sh, ksh, csh, tcsh and
bash) put together.
The reader may notice some similarities between the whois++ based URC and the Internet Anonymous FTP Archive (IAFA) templates described in[37,38]. The IAFA templates are an alternative method for associating meta-information with Internet resources. The most significant difference between the two formats is that IAFA templates have different contents depending on the type of the object - e.g. the templates for mailing list, sound sample, image and document each have their own specific sets of attributes. As yet, the URC is not typed in this way.