Rule blocked: SEND304 / CORE-737

SEND304 states: If CDISC published Controlled Terminology applies and the collected value is synonymous with a CDISC Submission Value; the synonymous term must be mapped to the CDISC Submission Value.

For many controlled terms, the synonym(s) are in the CDISC Library. So, a lookup should be possible, but for long lists (e.g. for LBTESTCD, UNIT), this may be costly.

The possible algorithm is described in Jira: https://jira.cdisc.org/browse/CORERULES-737:
- first one checks whether the variable is under CT
- if so, check whether the value is one in the CT list
- if not, check whether the value is a synonym of an existing value in the CT list.

For the last part, there is no function yet.

REMARK: I think it should be discussed with the SEND team what the priority of developing such a function is,
also as, for such a case, an issue will already be reported by some other SEND rules.
Furthermore, there may a conflict with the rule(s) for extensible codelists ...

Start with the SEND304 rule and the linked CORERULES-737 Jira issue, then inspect how controlled terminology is checked against the CDISC Library. The payload names no files or tests; done would require an agreed synonym lookup approach, handling long controlled-term lists, and resolving its relationship to extensible-codelist rules.

Written by the indexing model from the issue text.