The tag file defines two attributes: the name of the required field and an optional error message.
Validation controls enable you to check for a required field, to test against a specific value or pattern of characters, to verify that a value lies within a range, and so on.
Required field validation: Omit some of the required fields and make sure system gives proper error messages.
Try leaving a required field blank or putting an invalid date into a date field, and you'll see those errors when you try to save, as shown in Figure 6-5.
Common Name is a required field and is typically used as the most granular level of identity.
Preferably, use instructional text to indicate required or optional fields, but asterisks also work for required fields.
Reminder: if the customer required field house, can inform the customer service staff to your schedule, and leave your telephone number.
Fill out the remaining required fields and submit.
