OpenVMS System Services Reference Manual

This document is a technical reference manual for HP OpenVMS system services, covering those with names starting with A through GETUAI. It provides systematic descriptions for each service, including:

• Purpose: A concise description of what the service does (e.g., aborting a transaction, creating a mailbox, managing privileges).
• Format: The syntax required for calling the service from C and other languages.
• Arguments: Detailed definitions of each input and output parameter, including usage, type, access mechanism, and specific requirements.
• Description: A detailed explanation of how the service functions, its preconditions, and any potential side effects.
• Condition Values Returned: A comprehensive list of success and error status codes that the service may return.

The manual is structured for system and application programmers and covers complex features such as 64-bit addressing support, distributed transaction management (DECdtm), and authentication and credential management (ACM).