How to set up required fields in HCSF forms

I can't easily make fields in an HCSF form be required, despite the use of the isRequired and requiredMsg values, which appear to do nothing.

If I associate an HCSF field with a metadata field that is set up as required in ConfigMan, then that works, but it doesn't work if I try to make it required through the use of a rule (although the rule does work for a traditional checkin). I'd rather not make required metadata fields for all the form fields that I'd like to be mandatory. I've tried playing around with the isCheckin and isFormSubmit values both in my form code and in my rules, but so far no luck.