Bug report: issue with BNF to DM+D mappings or conversion

Summary

It's possible that:

• importing the BNF to DM+D mappings is failing somewhere
• there's some issue with converting codelists.
• possibly more likely, the BNF data is outdated (see below)

What did you do and what did you expect to happen?

From Andrea on Slack to tech support:

Hello, I've created a series of codelists for BNF chapters (example for Chapter 1: BNF codelist) which I've also converted to dmd. However, when I look at the tree for the dmd codelists some items are excluded, which I'm pretty sure should not be. There is no way to manually add those codes to the dmd codelist, and I can't see how to "fix" the BNF codelist so they are included. Any help?

Impact of the bug

It's happening consistently, and preventing the DM+D codelist from matching the original BNF one.

Start by reproducing the conversion using the linked BNF and DM+D codelists, then compare the excluded items with the source mappings. Trace whether the mismatch comes from importing the BNF-to-DM+D mappings, codelist conversion, or outdated BNF data; done means the cause is identified and the converted codelist matches the expected source terms.