I'm trying to enter data validation for a field in my template to require the participant to enter 4 characters (letters or numbers). I only see "maximum" allowed. The field in my template is the final four digits of a credit card payment (first 12 digits are in a separate masked field). I tried "string" allowing letters and numbers (using letter O in place of number 0 due to problem with csv dropping leading zeros) but I'd like to make the field error proof by requiring 4 (no more no less) characters in the field. Solution?
The validation you are looking for is the Regular Expression.
Regular Expressions allow for defining a pattern of characters and/or numbers. It can get deep quick, but your use case is pretty simple.
four digits between 0-9 would be :
However, this type of validation is only available at the Business and Enterprise levels of service.
If you are on the Free, Individual or Team level of service, the Regular Expression option will not be available to you.