Regarding these two Japanese go terms: 手合い (teai) and 置碁 (okigo). I was under the impression that 手合い refers to the handicap under which a particular game or series of games is played, such as a jubango, where the 手合い may change during the course of the match. Whereas 置碁 is handicap go in general, as in the books Handicap Go and Get Strong at Handicap Go.
If so, then handicap go should not be an alias for handicap. Okigo should be an alias for handicap go. Help requested from folks with greater knowledge of Japanese.
Bob McGuigan: teai refers to playing conditions in general, such as time limits, or how many games there would be in a match. If there were a handicap it would be included as part of teai. Okigo refers specifically to handicap go, but not to the handicap in a particular game. I think okigo is used only in the case of actual handicap stones, not for direct or reverse komi, or handicaps such as always playing black.