Old horn notation used in Chinese film music?

I just argued with my dad (a very good film composer) over bass clef old notation. He said that he learned it that way and the players who recorded had no problems. Is it because Chinese composers learned from the "russian school" and have little to no contact with the rest of europe or did I missunderstand something. All the online sources say old horn notation is obsolete. Can somebody explain it to me?

3 minutes ago, Chemathmusician0510 said:

All the online sources say old horn notation is obsolete.

Yeah me too, I only know that the old horn notation in bass clef and the actual pitch perfect fourth higher instead of treble clef and perfect fifth lower nowadays is obsolete.

And, Chinese always have little to no contact to the rest of the world lol.