I would say arc42 is quite recognized documentation framework among software architects in Germany. My team is working with one major German automotive group and we/they are using slightly modified arc42 to document architectural parts + requirements for one of their core sw platforms.
Also as far as I’m aware arc42 is a part of training courses for iSAQ certification for sw architects.
Also as far as I’m aware arc42 is a part of training courses for iSAQ certification for sw architects.