1.xxyy is an online buzzword, which comes from e station. It is the collective name of seven up main groups in the station. Because xxyy seven people are "forced" to form a combination, they will say "we don't know each other" whether they meet in business or attend various activities.
2.xxyy can also be understood as "rare jade". In the game League of Legends, when players want to express a hero or equipment is very scarce, they will use "xxyy" to describe it.
The above is part of the explanation about xxyy. Different scenes have different meanings. For more information, please consult a professional.