Help Identify a fuse.

[salvatore1]

I found a blown 15 amp fuse and was hoping someone knew what it was for. Its located in the hidden fuse block under the dash on the passenger side. There are two rows to this fuse block - one in the front and one farther behind. The one I'm referring to is the row in the back second fuse in from the left. I stuck a mirror under there (one of my wife's compacts) and tried to make out what it says - something like "a common"..........I'm not really sure. I replaced it (whatever it is) but dont know what I just fixed.

Thanks