Pidgin Algol
In computer science, Pidgin Algol refers to an informal notation that blends syntax taken from an ALGOL-like programming language with some other mathematical notation, such as that of set theory. Hence the name: the mixture is a programming language analogy to a pidgin in natural languages.
It is used to describe algorithms where control structure is made explicit at a rather high level of detail, while some data structures are still left at an abstract level, independent of any specific programming language.