> BSD sysexits.h (which is also in GNU libc) defines several exit codes in the range 64-78. These are typically used in the context of mail delivery; originatin

> BSD sysexits.h (which is also in GNU libc) defines several exit codes in the range 64-78. These are typically used in the context of mail delivery; originating with BSD delivermail (the NCP predecessor to the TCP/IP sendmail), and are still used by modern mail systems such as Postfix to interpret the local(8) delivery agent's exit status. Using these for service exit codes isn't recommended by LSB (which says they are in the range reserved for future LSB use) or by daemon(7). However, they are used in practice, -- https://pkg.go.dev/git.lukeshu.com/go/libsystemd@v0.5.3/sd_daemon#pkg-constants https://pkg.go.dev/git.lukeshu.com/go/libsystemd@v0.5.3/sd_d...