Other CRMs let us add display and input masks to custom fields. I'd like this feature in custom fields (opportunity and contact) and custom values. This is especially helpful for forms and surveys. For example if you are asking for a social security number. The number must be ###-##-####. But the plain number custom field allows free rain of the amount of numbers. We should be able to mask this in the field so users and customers have to fill out the specific numbers and it automatically adjusts adds dashes, etc.