o. a. should not mean "oder ähnliche", that would be "o. ä."
Also "o. a.", "o. g.", "o. A.", "Wz", "z. Hd. (zu Händen - if you do not have umlauts, you'd need to expand "Haenden") are not that common in everyday usage (they do exist). I could give you "usw." ("und so weiter" - and so forth, same as "etc."), "bspw." ("beispielsweise" - as an example, same as "e. g." in English). Yeah, we also do like it. And of course "RflEttÜAÜG" ("Rindfleischetikettierungsüberwachungsaufgabenübertragungsgesetz" - law concerning the re-delegation of the tasks of supervising the labelling of beef)
Oh, and to keep this on topic: isn't Luna great? And Gracie too?