Can the first key-value-pair in a URL query be empty?

I've recently coded an AJAX logic where I purposefully generate URLs that start with ?&, like this:

http://ift.tt/2dizjUq

I admit, that decision is partly based on laziness but honestly, I don't see any concern with this, from a technical standpoint.

Now, a colleague of mine asked me today how safe-to-use this is in regards to support of old/shitty browsers (such as IE *cough, cough*). Since I didn't find anything in the internet, I'm asking you guys/gals.