This has been around since 2.1, but the following statement exists on participant in ProcedureNote and ReferralNote

SHALL contain exactly one [1..1] @typeCode="IND" Individual (CodeSystem: HL7ParticipationFunction  2.16.840.1.113883.5.88 STATIC) (CONF:1198-8505).

TypeCode comes from HL7ParticipationType, so the "IND" refers to "indirect".

Likely this is just a wording change (now only present in the ^short in the SD format), but wanted to confirm that we intended this to be Indirect, not Individual.

Note that Transfer Summary has the correct code system:

SHALL contain exactly one [1..1] @typeCode="IND" indirect (CodeSystem: HL7ParticipationType  2.16.840.1.113883.5.90)) (CONF:1198-31872).