Police chiefs have banned IT staff from using the word blacklist over fears it is racist.
The computer term whitelist — used to denote a list of acceptable contacts — has also been outlawed.
In an email, Scotland Yard warned staff the words were no longer “appropriate”.
Security services chief Brian Douglas wrote: “IB Information Board are uncomfortable with the use of the term Whitelist and I presume Blacklist.
“I am sure we can appreciate the sensitivity around the use of such terminology today so please ensure it is no longer used.” He suggested using green and red list instead.
Sources at the Met — where 20 officers are under investigation over alleged racism — branded the decision “bizarre”.
One said: “Do we really think these words are discriminatory? The truth is they’re nothing to do with race whatsoever and are very common IT terms. Banning them won’t solve any genuine problems the Met has with racism.”
Scotland Yard said: “This is not a change in policy. It is a change in internal Information Communications Technology terminology which reflects a more appropriate use of language.”