It will be increasingly important that when IATI involves external vocabularies (via vocabularies) codelists (as non-embedded lists) and/or registries (in terms of organisation registration agencies) within the standard, there might need to be some process or criteria through which these are assessed, prior to being added.
As @Wendy states:
However, I should also mention that one thing we would need to be mindful of is that the non-embedded codelist update process has enough oversight to ensure that only valid entries for formal vocabularies (that are themselves well managed and likely to endure) are added.
Via the Open Ag Funding project we've started to think about this - there's some thoughts in an initial post on what "a good codelist looks like".
I can happily replicate here, but would welcome any thoughts and feedback on this topic.