I find that often times, service calls get closed without a valid comment entered into the solution field. Although the field is mandatory, users work around it by hitting the 'space bar'. I thought I read somewhere that you can create a rule to enforce users to input 'valid' or more meaningful text into the solution field. Is this true?
Users are always going to find a way around requirements for non-selection fields. If it were my shop I'd build a Crystal Report to show me the tickets where the count of characters in the solution is less than 10, grouped by Assigned To. Then I'd get the powers that be to apply boots to posteriors.