What happens if the action field in a <form> has parameters?

Question

Is there a well-supported, common behavior that I can expect if I do something like this in HTML:

Answer 1

If the method attribute is set to GET, the browser drops the querystring parameters from the action attribute before constructing the form argument values.

So in your example, the request to the server on submit will look like: /somePage.html?param2=value¶m3=value

So no, when the method is "GET", as in your example, there's no reason to do this.