PGNXML Standard for Chess Notation

1.0 Introduction

This is a proposed standard for the communication and storage of chess game information. This is a full implementation of the PGN (Portable Game Notation) standard, including support for FEN and subvariations. Since this is a proposed standard, I'd like to elicit feedback from within the chess community on its usability and functionality.

2.0 Overview

PGNXML is currently implemented as an XML Data Schema. This was the original Schema proposal to the w3c. This work is now refered to as XDR. The current plan is to migrate it to the new XML Schema specification as soon as some conforming implementations are available for testing.

2.1 Goals

One of the guiding goals of the PGNXML standard was to presume a simple web browser client which will not have much chess knowledge and just needs sufficient information to navigate the XML and provide a playback through the provided PGNXML game.

2.2 The PGNXML Schema

The current schema is contained in pgn.xdr. The associated conforming xml file is in p2x.xml. The p2x.xml file was generated from the pgn_test.pgn source file using an automated conversion routine, which will convert any standard pgn file to a PGNXML conforming XML file.

2.3 ChessPGN Tool

The ChessPGN tool is useful for converting from a generic PGN format file to a PGNXML formatted file. The conforming output can then be tested against the XDR file.

3.0 The PGNXML Hierarchy

The primary XML root is <PGNGAMES> A PGNGAMES element will consist of 0 or more <game> elements. Each <game> element must contain 1 <info> and 1 <moves> element.

3.1 <info>

The info tags are enumerated in the XML Schema, but the basic tags are:

<Event>
<Site>
<Date Year="nn" Month="nn" Day="nn" >
<EventDate Year="nn" Month="nn" Day="nn" >
<Round> (numeric content)
<White Elo="nn" USCF="nn" NA="xx" Country="xx" Type="xx" Title="xx">
<Black Elo="nn" USCF="nn" NA="xx" Country="xx" Type="xx" Title="xx">
<Result>
<ECO>
<Termination>
<Annotator>
<Mode>
<PlyCount> (numeric content)
<Prologue>
<Epilogue>
<FEN ActiveColor="xx" CastlingAvailability="xx" EnPassantTargetSquare="xx" DrawCount="nn" MoveCount="nn">

3.2 <moves>

A <moves> tag consists of:

<move n="nn" state="xx" annotation="xx" promote="x" from="xx" to="xx" NAG="nn" display="xx">
- <text> (move comments)
- <move> (variation)
- <end> (end of move sequence)
  - <text> (end comments)
<end> (end of move sequence)
- <text> (end comments)

Issues

PGN uses both a Date and EventDate tags. Do we really need both? Should EventDate be subsumed within the Event element?

Brad Merrill <zbrad@cybercom.net>

Last modified: Tue Sep 12 11:19:07 Pacific Daylight Time 2000