I don't believe we're getting the full picture, and there's no description of what OP is actually looking to do, however READONLY fields are useful in various circumstances, say for example a UI that allows users to delete something (as suggested here), prompting them with a page they can submit, cancel but not alter submission details for a record to be removed makes sense. Hopefully there is some sane, session based checks being made behinds the scenes, as it's fairly easy to mess around with such things if they are blindly accepting user input.

Ah. I overlooked the sole point of the form -- to delete an existing entry rather than the typical editing screen. Thanks for this explanation and tip!