Upon the issuance of the 1905 / 1919 watermarked Yacht Issues, imperforate sheets were printed of several of the values for the archive of the Reichsdruckerei (Reich Printing Works).
Proof printings of the 20-, 45-, and 60 Heller values of the unwatermarked Yacht Issues were printed in several trial colors.
Prior to printing of the first Yacht Issues, a proof was produced of the 2 Pesa issue.
Proof printings of the 2- & 3 Rupien values were printed in trial colors that vary from the colors of the eventual issues.
Upon occupying Mafia Island, the British used a handstamp to overprint German East Africa issues for use by British forces in the area. The first issues were overprinted ‘G. R. / MAFIA’, and they can be found with black or blackish-violet ink.
In the late 19th century, the coastal area of Quionga belonged to Portuguese Mozambique by treaty, but was culturally German. Despite multiple treaties designating the area as Portuguese, the German East Africa made repeated assertions of control over the area.