-- Posted by Sachacohen2 at 9:59 am on Feb. 22, 2008 How do you write the validation rule for when you only want letters allowed no numbers? Or what do you write when you only want numbers to be allowed nothing else? -- Posted by DefaultTo0 at 11:11 am on Mar. 18, 2008 Put 'number' as the data type - this will serve for all basic needs. I believe that there is an input mask that you can use to specify only numbers.  I know that the letter 'L' means 'allow one letter'.  Unsure how to specify that it can be of any length though.