i can't find any information inside the w3c html strict spec http://www.w3.org/TR/html4/sgml/dtd.html
I don’t think there’s a maximum number of input
elements in a form given by the spec, if that’s what you are asking. If you have many inputs and want to make sure the form works, you’ll have to try on the clients you support. And of course, it would be much better to redesign the form, if that’s possible.