Sljedeće ključne riječi ne smiju se koristiti:

• C(++):

__asm	__asm__	__environ	__getpgid	_asm	_asm_	_rename	access
acct	alarm	asm	brk	chdir	chown	chroot	close
closeall	confstr	crypt	ctermid	daemon	dup	dup2	encrypt
endusershell	environ	euidaccess	execl	execle	execlp	execv	execve
execvp	fchdir	fchown	fdatasync	fexecve	fileno	fopen	fork
fpathconf	fsync	ftruncate	ftruncate64	get_current_dir_name	getcwd	getdomainname	getdtablesize
getegid	getenv	geteuid	getgid	getgroups	gethostid	gethostname	getlogin
getlogin_r	getpagesize	getpass	getpgid	getpgrp	getpid	getppid	getresgid
getresuid	getsid	getuid	getusershell	getwd	group_member	isatty	lchown
link	lockf	lockf64	mkdir	nice	open	pathconf	pause
pipe	pread	pread64	profil	putenv	pwrite	pwrite64	readlink
remove	rename	revoke	rmdir	rmdir	sbrk	setbuf	setbuffer
setdomainname	setegid	setenv	seteuid	setgid	sethostid	sethostname	setlinebuf
setlogin	setpgid	setpgrp	setregid	setresgid	setresuid	setreuid	setsid
setuid	setusershell	setvbuf	sleep	socklen_t	symlink	sync	syscall
sysconf	system	tcgetpgrp	truncate	truncate64	ttyname	ttyslot	ualarm
unlink	unlink	usleep	vfork	vhangup

• Pascal:
• assign
• reset
• rewrite
• uses
• BASIC:
• Nema zabranjenih riječi!
• Java:
• Nema zabranjenih riječi!
• BrainF*ck:
• Nema zabranjenih riječi!
• (tko bi rekao!)