When creating/editing global regular expression user must choose from following expression types:
- Character string included
- Any character string included
- Character string not included
- Result is TRUE
- Result is FALSE
Only the last two means regular expression and their description is confusing.
I think better would be to shorten the list to:
- Any substring from list (or just a 'Substring list')
- Regular expression
and move the result altering flag as a separate checkbox:
'Return FALSE if match' (or 'Invert result').
Note that currently there is no "Any character string not included" expression type, so the 'Invert result' checkbox must be disabled when 'Substring list' expression type is selected (Or alternatively support for this expression type should be added).