Some formats, like Custom sections, now use a generic "New section" as the default section name. This motivates the teacher to put a meaningful name to the section. However, the current section editing form allows the user to leave the name empty, but when the teacher does so, the section gets renamed as "New section", which is not advised.

On the other hand, formats like "weeks" use the empty section name to render the specific week dates. In those cases, leaving the name empty is a valid value.

The idea is to allow format plugins to define whether the section name is required. At a core level, topics will have the field required, while weeks will not. Regarding single activity and social formats, a decision needs to be made.