thanks for the help
like in the last responds: product_details.tpl get's the information from the the product.specific_references.
I have to check this now
I thought that it would be much easier... 😁 I found the translations, but this changes only in admin section. I hoped that it's just a translation or just a small text change, not modifying the complete code
Instead Mpn (which is shown in product details / front page) it should be "Phznr". The rest is okay. This little change is really annoying...