InfoPath Dev

Is there a forumula/xpath to convert/ restruct non utf-8 characters in a textfield. If we can't suceed, I atleast want to change them to white spaces before submitting the form. Example of some non utf-8 characters:- Trademark TM ™ and registered trademark ® Thanks in advance for your responses.

You could use custom validation to at least mark the field invalid, I think. I found a suggested pattern here, and tested it here - it at least found your ™ and ®. Your field could have custom validation - if the data matches the custom pattern of [^\x00-\x7F], mark the field invalid and give the user a message about removing the special characters.