User defined validations in manage formats to avoid fields or lines starting or ending with symbols.

Summary:

User defined validations in manage formats to avoid fields or lines starting or ending with symbols

Content (required):

How can we write user defined validation on let us say invoice number to avoid fields or lines starting with space or comma for PPR

Version (include the version you are using, if applicable): 23B

Code Snippet (add any code snippets that support your topic, if applicable):