Add new style for German journal "Deutsche sprache"

The guidlines are quite short and let some issues unclear. Therefore, I checked the style also by looking at a current article closely. (It is very probable that this was asked in https://forums.zotero.org/discussion/39057/citation-style-request-deutsche-sprache/ )
Okay, `et-al-use-first="1"`, but that is the same as what it actually is doing at the moment (standard? visual editor thing?). Moreover, I should do this in all author, editor, creator macros (yes, I see examples for that now). Was this the meaning of your 2nd sentence?