What would that be?
As Convert>Tag-Tag has a preview, you should see the immediate result, here: the string without that part in the brackets.
Also, as you can see the input field in the dialogue is labelled "Format string".
You copy and paste the string that I suggested into that field.
Now, a regular expression leads to no result (here: the string stays as it is) if the pattern does not match. So instead of giving
it would be better so see a real life string.
To see more about regular expressions, see the help:
There is, of course, the way to replace a string constant with nothing, e.g. with an action of the type "Replace" for TITLE
(revised by Salieri)
This works only for this exact string. if you have versions with "(revised by Clementi)" then it would not work - the regular expression would cater for both cases.