You can search on tickets that had the request type "Hardware" by searching the History field.
Thank you for the information.
I did some tests based on your suggestion. For a test I have 7x tickets with request type "Hardware". If I change one to request type "Software" and use the History field in search I get a list of over 200x tickets. It seems that "History" does search each field in all the tickets for the specific phrase.
Is there something I do wrong?