durangod
There is no way to pre-populate data for fields based on other fields. That’s what we call "Dependent Forms and Fields" which is coming in v2.0.
If a field is on the Contact Information Form the User will only see when creating their account initially, when creating a Ticket without being signed in, or when visiting their profile (if editable). If a field is on the Ticket Details Form it will appear on every single Ticket (unless specifically disabled by the Help Topic).
If you only want them to fill it out one time then I'd add it to the Contact Information Form so they fill it out when creating their account and then never have to worry about it again. If they do need to update it for some reason they can go to their profile and update it (or have an Agent update it that has the appropriate permissions). With this option though you wouldn’t see the value in the Ticket header; instead you’d have to click the User's name in the header to view their account details (so basically an extra click).
Cheers.
