This label is for communicative or mental information content—i.e., a message or contemplated proposition—expressed more directly than a Topic.
In English, this is usually conveyed not with an adposition, but with a content clause possibly marked by a complementizer:
Outside of English, Content may apply to adpositional or case marking of quoted speech (e.g., quotative markers).
Contrast Topic, which is for the subject matter of information, rather than the information itself.
Information that is thought or communicated.