Sams Photofacts index (Sim. to Ch.) meaning?

[MightyFrame]

In cross-referencing Photofact folder numbers to TV model numbers, I see a number of notations, and this one isn't quite clear to me:

(Sim. to Ch.)



It seems to be referring that model to something else, "Similar to Ch?"

If Sim = Similar, then what is Ch?

I know many here have long used Sams Photofacts, so hopefully it's obvious to someone.

Using index at

https://www.samswebsite.com/download..._VOL1_2002.pdf

Thanks always!

Best,
AJ