I was watching an anime ("The Royal Tutor"), and I noticed someone with an interesting name (presumably a pen-name) - 子子子子 子子子, which as far as I can tell is a reference to "Neko no ko koneko, shishi no ko kojishi". So I tried to work out what role this person had in the show, and it was given as 予告脚本. As best I can manage, this seems to mean "preview script", so did this person really get a screen credit for writing the script to the next episode's preview, or is there another translation I've missed?
予告 is a preview/trailer of the next episode of an anime or a drama, which is typically 15 seconds long. 脚本 is a script writer in this context. If the end credit really said something like
予告脚本 子子子子 子子子, then that's the person who wrote the script of the preview of that episode. As you have probably guessed, there is not usually a dedicated writer for a 15-second preview clip, but that's the only possible interpretation.
EDIT: Here's a tweet that says she was actually in charge of 予告脚本.