Existing Wording: As with other knowledge artifacts, logic is included by referencing a Library resource. Although the base resource allows for the measure to reference any number of libraries, for simplicity of managing sharing, this implementation guide requires that a measure reference only one Library, the primary measure library, and that this library contain all the named expressions required to define the measure structure.

Comment:

is this a constraint (SHALL?) or a recommendation? If it's contraining the base resource, is a profile needed?

Summary:

Library reference constraint for Measure?