CZJ vs Jena lenses

[aniramca]

I started to get a renewed interest on the manual lenses. I checked my Praktica LTL camera, purchased in 1974 and it has a 50mm f/2.8 T from Jena lens on it. The camera manual indicated that it was made by VEB Pentacon, Dresden, DDR. The manual did not mention any word about "Carl Zeiss"
I do notice in some photos in this forum showing Carl Zeiss Jena (CZJ) lenses.
So, I assume that the lens of my Praktica is made in East Germany, and not from Carl Zeiss at all? Is this correct? However, when I looked at the serial number of the lens - around 9,000,000 , it agrees with the CZJ production from 1970-1975. So, is it a CZJ or a Jena lens? Or they are the same?
The manual only said about T lens from Jena. Does T mean that this is a Tessar design lens?
Thanks for info.

[no-X]

There were 2 post-war Carl Zeiss factories: eastern Carl Zeiss Jena and western Carl Zeiss Oberkochen. They had some pursuit because of the Zeiss brand name and during the lawsuit they were prohibited to use the Zeiss brand for export goods. Because of this, Carl Zeiss Jena used "aus Jena" trademark and Oberkochen used "Opton" trademark.

But there are also some lenses marked "Jena" (or alike), which use Carl Zeiss Jena optical designs, but not CZJ barrels and marking:

http://forum.mflenses.com/is-it-a-real-cz-jena-t15507.html

[mflex-on]

And the classic names were shortened for the "export" models of CZJena:

B = Biotar
Bm = Biometar
S = Sonnar
T = Tessar

Some people say that the export lenses were better tested before they left the factory.

[Attila]