This may occur elsewhere in the spec as well, but I noticed it in the "Using Libraries" documentation. In the documentation several examples are used to illustrate points of the spec. In some of these, a FHIR data model is used. In others, it appears that a QDM data model is used (e.g., "Diagnosis" and "Encounter, Performed" data types). In addition, some of these examples are clearly pulled from eCQMs (as they use "Measurement Period".

Given that this is a FHIR IG for encoding Clinical Guidelines as CDS (are most likely as CDS anyway), I think examples w/ QDM and eCQM logic may be confusing to readers. I'd suggest always using a FHIR data model in examples and sticking to logic appropriate for CDS (e.g., not referencing "Measurement Period").