Confluence content has concepts such as versions (1, 2, 3,...) and status (current, draft), however, there doesn't seem to be a developer guide explaining these concepts. 

For example, the guide should explain how/when to specify the status query parameter on various REST endpoints such as POST /wiki/rest/api/content/{id}/child/attachment. It should also explain the versions number scheme (does version 1 correspond to not yet published?).

Such a guide may have prevented the the creation of the community topic Attaching a file via RestAPI to a Confluence page draft.