Unknown chords

Ehm i got a question, i recently stumbled upon a chord which i didnt know. It was a D with a little 6 written on the top right end of the Letter (like the mathematical "to the power of") and a 4 at the right bottom underneath the six. So i guess that would be a D with a 4th as the bass note and a 6 in the chord? What would be a fingering for this?
And another one had an "8-7" at the right bottom of the Letter. so what does that mean?

Im kind of new to those strange chord shapes ^^

But any help is widely appreciated

Jazz had a lesson on some of those...

Names of Chord Symbols

ah cool i found my chord. God bless wikipedia. It wasnt in Jazzes List:

http://de.wikipedia.org/w/index.php?title=Datei:Quartsextakkord.JPG&filetimestamp=20070327094349

they dont have that article in english

http://smu.edu/totw/invert.htm -> This is what you are looking for

http://www.musictheory.net/lessons/html/id47_en.html -> Taking the next step in the information you asked for

Hope this helps a bit