As part of 1.04, we plan to introduce a machine readable way of mapping attributes to codelists - http://support.iatistandard.org/entries/27805388-Mapping-between-codelists-and-schemas
Part of the "single source" plan is to only have a single source for each piece of information. In the case of the codelist mapping, we propose that the canonical source will be this new machine readable mapping. A natural consequence of this approach would then mean we would remove the human readable codelist mapping from the source schema on github. (i.e. remove the URLs to codelists on iatistandard.org from the schema annotations)(Full diff here - https://github.com/IATI/IATI-Schemas/pull/57/files )
However, I understand that having information about codelists in the schema description annotations is useful to some, and that there have infact been calls to have more information within the schema rather than elsewhere, so I've added this as a proposal for the upgrade forum.
To mitigate disruption, it is possible to make availible a 'generated schema' that has codelist information added to the descriptions programatically. However, this 'generated schema' would have to be served from a different url.
There is a pull request for this change on github at https://github.com/IATI/IATI-Schemas/pull/57 - this also links to the development version of the 'generated schema'.