enabled property
Enabled is the whole-playbook lever. Absent reads as ON; an explicit false makes resolution skip this playbook entirely and fall through to the next tier, rather than serving an empty journey.
Please note: This property should have been non-nullable! Since the specification file does not include a default value (using the "default:" property), however, the generated source code must fall back to having a nullable type. Consider adding a "default:" property in the specification file to hide this note.
Implementation
bool? enabled;