white hat
= W =
whizzy
whitelist n.
The opposite of a blacklist. That is,
instead of being an explicit list of people who are banned, it's an
explicit list of people who are to be admitted. Hackers use this
especially of lists of email addresses that are explicitly enabled
to get past strict anti-spam filters.
--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.