Oe : a diphthong, employed in the Latin language, and thence in the English language, as the representative of the Greek diphthong oi. In many words in common use, e alone stands instead of /. Classicists prefer to write the diphthong oe separate in Latin words.

Example:
How do I get custom firmware like Oe for my psp?

Taxonomy
Ö, languages, alphabet, O-umlaut, dots, Ốố Ồồ, free encyclopedia, character, Scandinavian languages, Historically, phoneme, Swedish alphabet, Germanic languages, Finnish alphabet, Estonian, Icelandic alphabet, from A to Z, Typography.

Defination from the web:
Ö in the Swedish and Icelandic alphabets historically arises from the Germanic umlaut, but it is considered a separate letter from O. ... In Swedish, ö is a separate word by itself, meaning island, and as such occurring in many island names, like Öland (Island land) and ...