how "inverse match" regex?

i'm controlling regexbuddy nonetheless i'm problem anyway thing :\

i'm guess line line file. i built "line model" review i want.

now i'd an opposite match... i.e. i wish review lines where there twine 6 letters, nonetheless wholly 6 letters not andrea, should i that?

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edit: i'll way uses regex, i don't know nonetheless python php, i'm doing thing initial learn regex :) there opposite types line, i wanted regex name form i'm prying in. once i got lines i've ask an filter only review famous value, i need others, that. (?!not-wanted) operative graceful fine, conclude you. :-)

i wish clarifies doubt :)