What form you use is irrelevant. If you area certified or licensed appraiser you can write the value on the back of a napkin and you have made an appraisal. You can even give it to them verbally and you have made an appraisal. However, if you make an appraisal without following the needed steps to have a credible opinion of value you are in violation of USPAP. The easier way to handle this would be to tell the client you want to use a form that is designed to report value. However, if you want to please them, you can do the same appraisal work (and charge the same price) that you would do with another form and report the value on the form they requested. Just be sure you keep adequate documentation of the work you have done in your work file. You will, of course have to write a narrative comment to report the value on this form. Because of that, I would consider charging them extra to use this form– that will probably solve your problem.