In Copenhagen 2019, Ghana explained that in order to use IATI transaction (or other) data in their systems they needed harder evidence e.g. an official document supporting the data. Therefore it would be useful to be able to link e.g. a transaction to a specific document which forms the underlying evidence.
Multiple IATI elements could be linked to the same document e.g. the activity title, budget etc could all be linked to the project document. Many transactions could be linked to a single transactions statement, but this would save a lot of time searching though the documents associated with a project to try and find the right one. Publishers could also link to the relevant part of their own websites as evidence for some IATI data.