This was at a time where Carl Zeiss Jena had been making lenses for Zeiss Ikon, Rollei etc, this stopped due to quality issues in Jena where supplies of specialist optical glass was spradic.

Jena used the red T on their coated lenses, Zeiss Ikon needed to ensure that people realised these Optons were different lenses hence the Zeiss Opton Tessar name and maybe used the Ғ symbol as an alternative.

These Zeiss coating were very good both from Jena and Zeiss Ikon, I have an early 50's CZJ T coated 150mm Tessar, however they do tend to have a blue bias with colour films. tThe T & Ғ coatinngs seem to be heavier coatings than the coated but unmarked cheaper lenses like the Novars.