SNAFU

SNAFU, /sna'foo prin'si-pl/ which stands for the sarcastic expression "situation normal: all fouled up", is a well-known example of military acronym slang.  The situation is bad but is a normal state of affairs. 

It is typically used in a joking manner to describe something that's working as intended. The acronym is believed to have originated in the United States Marine Corps during World War II.

en.wikipedia.org/wiki/List_of_military_slang_terms