HTML and CSS Reference
Similarly, the user may not alter a text-related <input> or <textarea>
form control that you designate as readonly with the attribute. These
elements are still part of the tab order and may be selected, and the
value of the control gets sent to the server when the user submits the
form. The user just can't alter the value. So, in a sense, a form control
rendered readonly is the visible analog of the <input type=hidden> con-
What is the point of all these hidden and unchangeable form elements?
Automation. By automatically generating enabled and disabled form ele-
ments, you can tailor the form to the user. For example, if the user in-
dicates on one form that she is female, a subsequent form may contain
that information in a hidden attribute, and certain elements in the form
may be displayed for familiarity while certain elements are disabled to
make the form easier to navigate.