One of the most neglected aspects of the discussion of topic-based writing is that of provenance.
Every technical document has provenance of some kind. It may be a highly structured and elaborate provenance, such as certification according to a standard performed by an outside agency, or it may be the implicit provenance of being published by a brand name company.
Because of the implied provenance (not to mention implied liability) that goes with the publication of content under their name, most companies have some more or less formal and rigorous process for proving documents before they are released. In technical communications, this usually take the form of review and/or sign-off on a document by engineering and product managements (and sometimes legal).