'SE' does usually stand for 'special edition' where hifi and AV equipment is concerned.
Although this may give the impression that there is/was a 'standard' version available, many non-British manufacturers (especially the Japanese) release what they claim are slight varients of models destined for then rest of the world as tweaked versions for the UK market.
Therefore it's not uncommon for a model suffixed 'SE' to have no standard equivalent available in this country.