OK, I know that a "Dolby Stereo" soundtrack in the theater is exactly the same as "Dolby Surround" on LD or VHS. In the early days of Dolby Stereo there was some doubt about whether a matrixed sound format was compatible with mono equipment. Is this why some VHS releases (http://www.davisdvd.com/misc/ep4.htm) have Stereo (Mono Compatible) and some are Stereo Surround? Are the plain stereo soundtracks therefore recorded differently from the surround soundtracks, i.e. the surround channels simply added to the two main channels instead of being matrixed in with surround encoding?

I know that the UK VHS widescreen release in the early 90s had HiFi Stereo Sound - no mention of Dolby Surround - (this was the 1985 digitally remastered mix), but my 1995 release (features the THX remastered mix) actually has the Dolby Surround logo on the box.