This has been this way since at least the Companion Guide, possibly since 2.1:

SHALL contain exactly one [1..1] code (CONF:1198-14378).

• This code SHALL contain exactly one [1..1] @code (CONF:1198-14697).
• SHOULD be selected from ICF (codeSystem 2.16.840.1.113883.6.254) OR LOINC (codeSystem  2.16.840.1.113883.6.96) (CONF:1198-14698).

That says LOINC, but then lists the OID of SNOMED. Which should it be?

Suggest using LOINC, since that's what most of our clinical statements use, and that's also what the example has. But wanted to check with the community.