ipcrm(1p)
The Base Definitions volume of POSIX.1‐2017, Chapter 8,
Environment Variables, Section 12.2, Utility Syntax Guidelines
The System Interfaces volume of POSIX.1‐2017, msgrcv(3p),
msgsnd(3p), semget(3p), semop(3p), shmat(3p), shmdt(3p),
shmget(3p)