ULTRIX Worksystem Software X Window System Protocol: X Version 11

This document, titled "ULTRIX Worksystem Software, X Window System Protocol: X Version 11" (Order Number: AA-MA98A-TE), describes the precise semantics of the X11 protocol specification. Published by Digital Equipment Corporation in 1988, it serves as a foundational technical reference, independent of any specific programming language.

The primary audience for this manual is application programmers and system engineers who need a deeper understanding of the X Window System or who intend to implement it in other languages. It explicitly states that it is not a guide for writing X applications, C programming, or general X Window System implementation.

Key areas covered in the manual include:

• Fundamental Concepts: Definitions of terminology, detailed descriptions of protocol formats (requests, replies, and errors), syntactic conventions, and common data types.
• Input Devices: Discussions on keyboard-related issues (including KEYSYM encoding in Appendix A) and pointer-related issues.
• System Elements: Lists of predefined atoms and details about the connection setup and close processes.
• Protocol Operations: Extensive descriptions of each core protocol request, such as window creation and manipulation, font handling, graphics contexts, colormap management, cursor definitions, and host control.
• Events and Concurrency: Explanations of various events that can be generated by the X Window System and server control flow issues.
• Technical Appendices: Comprehensive tables for KEYSYM encoding across various character sets (Latin, Kana, Arabic, Cyrillic, Greek, Technical, Special, Publish, APL, Hebrew, and Keyboard) and a detailed bit and byte-level specification of the X protocol encoding.