This bookmarklet makes the browser ignore autocomplete="off" temporarily, allowing you to save passwords even on sites that use autocomplete="off". Should work the same for form data.

Remember Password bookmarklet: https://www.squarefree.com/bookmarklets/forms.html#remember_password

Sadly that didn't work. I clicked it and nothing happened. I navigated to one of the pages to see if it was enabled and just didn't notify me, but Firefox did not ask me, "Do you want to remember the username and password on this site?"

Is it a Windows / Mac incompatibility problem? (I have a Mac.)

Can you post a link?

You can use this bookmarklet to see if input forms have an autocomplete attribute and the value.

javascript:(function(){var c=0,f=0,t1=t2='\n',A='autocomplete';function R(w){try{var di,i,j,x,r=1;di=w.document.getElementsByTagName('INPUT');for(j=0;y=di[j];++j){if(y.attributes[A]){c++;t2+=c+': '+(y.name||'#'+y.id)+' ('+y.getAttribute(A)+')\n';y.style.backgroundColor='#ff9';}}}catch(e){r=0}return(r)}R(self);var i,x;for(i=0;x=frames[i];++i)R(x);{alert('Input: '+c+t2)}})();

Now the site has saved my ID, which is what I wanted it to do. I'm not sure if the first bookmarklet worked, and I didn't know it until just now, or if it just happened luckily.

Regardless, the problem is solved now. I think for security purposes, it's best that I don't have the browser save my password, so the ID is sufficient.

Thanks for your help!