This is a .NET regex specific modifier expressed with n
. When used, unnamed groups (like (\d+)
) are not captured. Only valid captures are explicitly named groups (e.g. (?<name> subexpression)
).
(?n)(\d+)-(\w+)-(?<id>\w+)
will match the whole 123-1_abc-00098
, but (\d+)
and (\w+)
won't create groups in the resulting match object. The only group will be ${id}
. See demo.