Rule blocked: CORERULES-716 (SEND-282)

I would like to have an operator that compares a list of values in the SDTM/SEND value, separated by a given delimiter (argument), that checks whether all the values in the list are members of the controlled terminology for that variable.
Reason is rule SEND-282 "If multiple specimen types are used for a calculation (e.g., serum and urine for creatinine clearance), then this field should be populated with values from the (SPEC) Controlled Terminology codelist delimited by a semicolon".

For example, the value of LBSPEC would be the list "**SERUM;BLOOD;URINE**" which then needs to be compared with the CDISC-CT "Specimen" list (C77529).

I presume such an operator (or operation) would require the SDTM/SEND value to be splitted on basis of the delimiter.
P.S. There are other similar SEND rules, but that use other delimiters ... :-(