This section states as follows.

The Document Type value set includes all LOINC values whose CLASSTYPE is LABORATORY in the LOINC database

However that is inconsistent with section 12.167.1.1 below, and with the LOINC Database Structure documentation. The correct value for the CLASSTYPE field is "1" in the database, not "LABORATORY". I think the actual value set content is correct, we just need to fix the definition.