Headlight Bulb Change and Yellow Bulb Inside
 

I am going to replace a burn out headlight bulb on my 1997 Taurus, and as a result will replace both sides to be consistent.

My question is what is the yellow bulb next to the headlight bulb inside the assembly? I know it is not one of the turn signal bulbs.

I find no mention of it in the manual. Suggestions?

Front parking light lamps ?