I once heard that when you have movie film scanned, or video printed on film, etc., the processing company prints information in the border of the filmstock, tracing the work to them (like a company name, or address or something). Any truth to this? Thanks.

Film has 'keykode' edge numbers that Kodak or Fuji burn in when the film is made. These numbers are useful for identifying the film footage during the post production cycle.
That's about it. Nothing VooDoo or strange there. Some cameras also burn in a time code , also on the edge of the film.
-Les