"operators" - key terms from Wikipedia

air traffic control operators
allow operators
amateur radio operators
annihilation operators
binary operators
boolean operators
bounded operators
cable operators
compact operators
creation and annihilation operators
delta operators
dnsbl operators
enigma operators
eod operators
fixed line operators
force recon operators
forecon operators
hrt operators
irc operators
ladder operators
linear operators
list of mobile network operators
logical operators
macross operators
mathematical operators
military operators
mobile network operators
mobile operators
mobile virtual network operators
network operators
new operators
normal operators
operators
operators	include
operators	may
operators	within
power pool operators
private operators
quarry operators
query operators
ride operators
set of operators
steadicam operators
ternary operators
tone mapping operators
tour operators
transit operators
unary operators
unitary operators
various operators