Previously, I assumed "Inst. Owned" meant the percentage of the company's stock that was owned by the company (viz. not floated), then I started to believe it meant the percentage of the stock which was owned by institutional investors. I still believe/assume that, but now I see AOL is 103% "Inst. Own", which carries me to the temporary assumption that AOL is being shorted right now?
'Inst. Owned' almost surely means "Institutionally Owned".
With respect to the 103% ownership reported:
Discrepancies caused by varying time lags in reporting ownership may skew the results
Second, and perhaps most likely, is due to short selling. I might own 100 shares, lend them to Bill, and Bill might sell (short) the stock to Nancy. In this case both I and Nancy might report owning 100 shares.