Help with german markings

[Hellcat]

Hello, I´d like to know the meaning of this markings on a 88 mm shell:

529 f DL 1938

I think "DL" is the acronym of the factory

Thank you for your aid

 

[Alpini]

If you wrote down all numbers then it's the Deutsch-Luxemburgische Bergwerks und Hütten Aktiengesellschaft. If there is another number behind the DL then it's a code for a different factory.

 

[Hellcat]

Thank you very much