At the current time documentation for the validation feature is limited to the following text. A standard error message will be presented to the end user. If Yes, select a comparison type. Type can be Exact , requiring an exact match. Enter the permitted values in the Valid Values input field, one per line.
Case is sensitive.
Type can be Range , indicating a high and low range for a numeric field. The range end points should be entered on the first and second line of the Valid Values input field. Enter the low end point first. Type can be RE , indicating a regular expression. Enter a regular expression on the first line of the valid values input field.