Which incident type do these characteristics describe: some or all of the command and general staff are activated as well as division or group supervisor and/or unit leader positions, the incident extends into multiple operational periods, and a written IAP is required?

The characteristics described pertain to a Type 3 Incident within the Incident Command System (ICS).

Type 3 Incidents are significant in scope and complexity, requiring a coordinated response that may involve multiple agencies and jurisdictions. The activation of Command and General Staff positions, such as the Operations Section Chief, Planning Section Chief, Logistics Section Chief, and Finance/Administration Section Chief, along with Division or Group Supervisors and Unit Leaders, allows for specialized management of different aspects of the incident. For example, in a large wildfire or a significant flood event, the Operations Section Chief would oversee direct tactics for controlling the incident, while the Planning Section Chief would focus on developing the IAP and gathering intelligence.

From the perspective of emergency management personnel, Type 3 Incidents represent a critical threshold where the complexity of the incident requires a heightened level of coordination and planning.

Source: https://training.fema.gov/emiweb/is/is200c/english/instructor%20guide/is0200c%20ig.pdf