I ran into a situation which suggests to me that there is a limit to the number of input text boxes you can have in an HTML form. I'm developing a registration system for a sports event and wanted a form which would allow the organizers to edit several items for each entrant. I had one hidden input with the entrant's ID and two text-box inputs for the items I wanted to edit. I found that this wouldn't work for more than approximately 333 entrants. I tried one hidden input (ID) and one text-box input and found that it wouldn't work for more than approximately 498 entrants. In each case that is approximately 1000 inputs. I use the POST method to transfer the inputs.
I'm using PHP to process the submitted form, and the PHP program runs only if I observe the limit.
I've Googled around and have found some discussion along this line, and those claiming to be in the know say that that there is no limit for the POST method.