Whenever you're building a form, there are time when you need the submitter to type their answer within a certain format otherwise it cannot be accepted.
For example, needing the date to be entered in a MM/DD/YYYY format or a phone number as (XXX)-XXX-XXXX format.
To this you can use Field Validation which is available on Text Field on both a WebForm and SeamlessDoc (Uploaded PDF).
To do this on an Uploaded PDF you will hover your mouse over a text field and then click on More Options.
Then once you are in the Advanced field options menu you will scroll until you get to Field Validation and you will see a menu of set options and Custom RegEx to create your own validation:
If you are using the Custom Regex (short for Regular Expression) then you can create a custom code for a format that we don't have in the list of options:
We have created a 'Cheat Sheet' with common RegEx's for both types of forms (the codes will be different depending on the type of form):
To do this on a WebForm you will add a Single or Multi-Line input and then hover over the field and click on the Gear Icon and then you will be taken to the inspector where you can choose a validation: