The last part of an IRDI is the version number. When referencing an external dictionary, the version of the dictionary entry is likely not of relevance. Is it allowed to leave out the version number, and is this maybe even recommended?
Would be nice to have some clarification in the specification about it.

The question can up when we discussed in the context of PA-DIM, where a companion spec currently references a specific IRDI (with version number) and what the expected behavior would be if there is a new version of the dictionary entry. Reference the new version in addition, only reference the new version in the updated version of PA-DIM, etc.

Would be good to have a general discussion about this (also what is expected from an OPC UA client) when dealing with IRDIs.
Keep in mind that we use the IRDI as NodeId, and if this includes the version, a new version is a completely different Node.