@Cow A normalized version,
{{'7404876271'}}
, of that pattern is already on the number blacklist. You can use
!!/bisect-number 7404876271(?# no noram)
to determine which entries on the number lists match that pattern, which would tell you: Matched by
7404876271(?#No NorAm)
on
line 3017 of blacklisted_numbers.txt: 7404876271 found verbatim