Precedence of assembler options

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Assembler options are recognized in this order of precedence (highest to lowest):
  1. Fixed installation default options
  2. Options on *PROCESS OVERRIDE statements
  3. Options in the ASMAOPT file
  4. Invocation options
    1. Options on the JCL PARM parameter of the EXEC statement on z/OS® and z/VSE®, or the ASMAHL command on CMS
    2. Options on the JCL OPTION statement (z/VSE)
    3. Options specified using the STDOPT (Standard JCL Options) command (z/VSE)
  5. Options on *PROCESS statements
  6. Non-fixed installation default options

You can specify an option as often as you want, and in as many sources as you want. If you specify the positive and negative form of an option (for keyword pairs), or two or more different values (for a value keyword), these option specifications are conflicting options. If all specifications of a particular option are at the same level of precedence, the last specification takes effect, and a warning message is issued. If some conflicting specifications are at different levels of precedence, then the specification at the higher order of precedence takes effect, and (in general) the assembler issues a warning message for each option that is not accepted. A warning message is not issued if the higher level of precedence is a *PROCESS OVERRIDE statement, unless the option cannot be set by a *PROCESS statement.