PGNs

Portable Game Notation (PGN) is a plain-text format used to record chess games. It has become the de facto standard for exchanging games among players, databases, and software because it is human readable and easy for programs to parse.

A PGN file consists of two parts: a header and a movetext section. The header uses tag pairs enclosed in square brackets, for example [Event "World Championship"] and [Date "2020.12.31"]. Common tags include Event, Site, Date, Round, White, Black, and Result, with optional ones such as ECO and Opening. The header provides metadata about the game or event.

The movetext section contains the sequence of moves written in Standard Algebraic Notation (SAN). Moves are typically listed with move numbers, e.g., 1. e4 e5 2. Nf3 Nc6. The text may also include comments in braces, variations in parentheses, and numeric annotation glyphs (NAGs) such as $1 to indicate a move of special quality.

PGN originated in the early 1990s and was designed to be portable across software platforms. It is widely supported by chess databases, editors, and online services, making it easy to archive, share, or analyze games. While robust for moves and basic metadata, PGN does not encode every aspect of a game (such as detailed timing data) in its basic form; some software can extend PGN with additional fields, but standard PGN remains the common baseline.