Clarification of Terminology in Writers’ Sections, such as “Additional Material by”, et al.

Hi. I was just reading the comprehensive page stipulating all the writers’ section terms, and it covered almost all that I’ve seen.

But it didn’t seem to define “additional material by”—what it meant, where it’s appropriate. Two examples come to mind here. The first: AMERICAN ANIMALS (2018), directed by Bart Layton. Around the web, often credited as the only screenwriter; but elsewhere, the other names get named too.

I investigated a bit. Claudia Zie was simply a German dubber; haven’t seen another source credit her with any screenplay input. Jon Croker, his profiles on sites where he worked credited his input here as “production draft”. Googled and learned about that process! Another guy, I believe Peter Straughan? One website said his input was for Channel 4. (Which made sense, because I recall some name on an ‘80s movie, who was uncredited–their input said “writer: Channel 4 editor” or something.) Croker’s profile on the BFI website said the same thing regarding his work on Paddington 2. So my assumption is, and correct me if I’m wrong, that the other names with the same tag are on an equal footing with him? Or could they all have different types of contributions…?

So I found that all a bit perplexing and exhausting, just because I’m trying to create a comprehensive list of films I’d nominate in certain categories for awards. And for debut writer/director, it muddies the water if I can’t quite discern what level of involvement those additional material had in the script, so I was wondering if anyone can clarify that? I apologize for being garrulous. I can’t help it. It’s the writer in me. Keep in mind though, it’s not just THIS film. It’s any film with this indiscernible gray area in the writers’ section. Whom to truly credit, because I like crediting the uncredited who pitched in a legit amount towards the story and/or screenplay.

But then with the additional credit, it’s like….Do I credit someone who just conceived a few basic setting details or who shuffled some things in the script during production at the directors’ request? Kinda makes me wonder why those names sneak up into the main writers’ section instead of the script/continuity or additional crew. Alas, that’s all I’ve got thus far. There are other examples that baffle me, but for right now, that’s it.

Oh, and I took one look at the amount of names listed under the early ‘90s’ Disney animated movies’ writer sections. Oh my Lorrrrdddddd. Absolutely NOT.