This case-sensitive code system http://hl7.org/fhir/questionnaire-derivationType defines the following codes:
Code
Display
Definition
extends
extends
Changed:Indicates this Questionnaire includes all of the items and permitted answers present in the target Questionnaire, however it also adds additional items and/or answers. A QuestionnaireResponse against the referenced Questionnaire should be valid against the referencing Questionnaire. However, a QuestionnaireResponse against the referencing Questionnaire might not be valid against the referenced Questionnaire.
compliesWith
complies with
Indicates this Questionnaire is derived in a manner that ensures that QuestionnaireResponses completed against this form will also be valid against the referenced questionnaire. To be a valid constraint, linkId, item types, and item order must align and all required items and answers must be included. However, cardinality can be tightened and answers can be restricted. If a Questionnaire complies with a parent Questionnaire, that does not mean that the derived Questionnaire is considered to have the same validity as the parent Questionnaire.
inspiredBy
inspired by
Indicates that some portion of the content of this Questionnaire was drawn from the referenced Questionnaire. Responses created against this Questionnaire have no expectation of being valid against the referenced Questionnaire. linkIds, question text, answer choices, etc. may all vary and items may have been added or removed.