Defining special processing to occur when a file is closed

[PxPlus]

There are three special mnemonics that come into place with a file is closed:

• *X - Contains the name of a program, with optional entry point, to call prior closure.  This program can use LFA to find the handle of the file being closed.
• *C - Contains a string of data that will be output to the file prior closure.  This will NOT be sent to a Windows printer (*WINPRT*) unless opened in raw mode (*WINDEV*). 
• *R - Contains an OS command line to INVOKE after the file is fully closed.  Generally this would be to used to send the file to the OS spooling system or elsewhere such as email.

When a file is closed the system will look for the existence of these mnemonics and, if defined, will process them in the order defined above.

These may all be defined using the MNEMONIC directive.
https://manual.pvxplus.com/page/directives/mnemonic.htm