READONLY is a TYPE attribute value to the INPUT element for FORMs. A
READONLY field is a text entry field [like the INPUT TYPE=TEXT field],
but the data is only observable and can not be altered by the user.
The text is also dimmed/greyed visually.
This behavior can also be achieved with the INPUT TYPE=TEXT element,
along with other form elements by using the HTML 4.0/XHTML READONLY attribute.
This optional attribute constrains the number of characters that can
be displayed in the readonly field from the default specified value.
If the MAXLENGTH attribute is larger than the optional SIZE attribute,
the text field should scroll as necessary.
This indicates a default value for the readonly field. The value is
displayed, but may not be altered by the user. This value is paired
with the NAME attribute upon submittal to the form processing script.