In short, "pseudocode" is a simplified representation of actual game's code, usually written by reverse engineers to simplify the actual logic when explaining it. It does not necessarily represent the original high-level code exactly, rather it tries to highlight the algorithms behind it without revealing all the gory implementation details.
Pseudocode (derived from pseudo and code) is a compact and informal high-level description of a computer programming algorithm that uses the structural conventions of some programming language, but typically omits details that are not essential for the understanding of the algorithm, such as subroutines, variable declarations and system-specific code. The programming language is augmented with natural language descriptions of the details, where convenient, or with compact mathematical notation. The purpose of using pseudocode is that it may be easier for humans to read than conventional programming languages, and that it may be a compact and environment-independent description of the key principles of an algorithm.