Sets the range of characters the user can enter into this field or control.
If you want users to only enter uppercase letters in this field, enter AZ. This ensures that only uppercase characters in the range of A-Z are accepted. If you want both uppercase and lowercase characters, leave this value blank.
You can specify multiple ranges of characters by entering the parameters in pairs. For example, a value of admpzz indicates that only the following characters are accepted: a, b, c, d, m, n, o, p, and z. If you only want to allow a single character, then enter that character twice to specify a starting and ending range.
The setting for the field is checked during validation. Validation occurs only if the field or control value is updated through the UI, for example, if a value is updated on a page or if a field is updated in a table directly. If a field is updated through application code, then the CharAllowed property is not validated.