Question about my TV

[BR7]

OK I have the Vizio 32" VW32L.Well for the longest time I thought it only supported 1080i. I was messing around with my PS3 and I went in to the Video output settings and clicked custom,it then notified me that my TV supports 1080p.I made the appropriate settings and then popped in a movie and sure enough when I pushed the display button on my TV remote it shows 1080p on the screen.The thing that gets me is that I can't find anything in the book saying this TV supports 1080p so would this be false information I am getting or is it supporting 1080p?
Thanks