UX could deteriorate when using MaskedField on a not mandatory field


suppose there is an editor screen with a form.

One of the fields is an optional (not mandatory). To make things worse let’s say this field is the last one in the form.

Consider the following scenario:

  1. A user is filling up the form, and makes an error, e.g. enters just 5 digits out of the 6 required by the mask on that field.
  2. Then he/she presses Save button.
  3. Screen closes, leaving the user with false impression that everything went well. In fact, the field has been cleared by the mask and no value is saved.

Would it be worth having an option to make a masked field more explicit and verbose when it comes to wiping out a wrong value?