Sure, in osCommerce Configuration>Customer Details the details of Gender, Date of Birth, Company, Suburb, and State can be turned on and off.

But how do I modify the others in the list (Street Address, City, State, Zip, Country, and Telephone Number) to be not required?

I've been tweaking and adjusting the invoice for a week now and I cannot figure out how to remove the model number from the items in the invoice.

Can someone point me to the code to change for this?

Thanks as always!

For the sake of sharing, the way to do this is to set the minimum length to zero in the Configuration>Minimum Values admin page.

The go to /catalog/includes/languages/english.php and removed the *'s next to those field names where the field is no longer required.