Hello. Thank you very much for replying.
I also tried your suggestion not(regex(.,'[|\x27|\x5C&@;"/?+#$]')) before since I read this from other users as well. However, it doesn't seem to work in my end. So, I decided to use a different approach and it's actually working.
I already used constraint before. However, if I'm not mistaken, the user will only be able to see the constraint message when you click the submit button.
In my case, I want the error message to appear before the user proceeds to the next field in the form, and not during the submission of the form after filling out all the fields.
I have this idea in my mind to use an if statement in the relevant column, but I can't seem to form any. If you have any suggestion, I appreciate any hints. Thank you very much.