Here are the meanings of some short forms I like to use:
DNW: Die Neue Welt, the german name of”The New World”expansion; the last”big”expansion pack for Settlers IV, never released in English.
CP: Community Pack(aka as Große Feldzüge in German). The last official expansion pack for The Settlers IV. Never included(to my knowledge) in any Gold Edition or compilations, and fairly obscure as it basically consists of a compilation of fanmade maps based on famous battles. It was released shortly before Settlers V, and fixes a problem with the trojan’s music tracks.
GE: Gold Edition, usually the regular Gold Edition, or simply the”english version”of Settlers IV. Includes everything released internationally(lacks both expansions mentioned above).
GE+: Gold Edition Plus, a second german Gold Edition(which features the DNW expansion pack, but still lacks the Community Pack EP). The box will simply say Gold Edition.
PE: Platinum Edition(Platin Edition in German). Refers to a german-only compilation of Settlers I to IV. Is basically a GE+ that behaves a little differently(although the most important differences are in the Settlers III version).
GOG: Refers to GOG.com’s Digital Release, which was released in Midsummer 2013. It differs from other versions in some ways, but offers a slightly better compatibility with modern computers straight away.