HD or Not HD

[tandreu]

What is the difference between 1080i and 1080i HD.

I'm watching channel 81 and it says 1080i with the HD symbol in the corner.
Channel 83 says 1080i with no symbol in the corner.

Is one in HD and the other is not??

 

[Smthkd]

One program was original recorded by a HD camera. The other program was upconverted and not true HD.