How to use custom regex in Dropbox Sign

Custom regex is a method used in programming for pattern matching, and is a type of data validation. Supported JavaScript regexes would be supported in this custom data validation. 

Custom regex is a validation option for textbox fields on your documents.

To add custom regex:

1. Add a textbox field to your document.
2. Select the textbox.
3. Click the Validation dropdown in the right sidebar, and select Custom regex.
4. Enter your custom regex under Specify a regular expression, such as [A-Z][a-zA-Z]+,[ ]?[A-Z]{2}.
5. Enter a description under Regex label, such as “City, ST”. This text will appear in the error message that shows if an entry does not match your requirements.