Deltarune is an episodic video game, coming out in chapters. Each chapter has its own soundtrack album, usually titled “DELTARUNE Chapter 1 OST“ etc. The chapter number designates not the album itself, but rather, the game chapter that it belongs to.
Recently, there’s been a spree of edits surrounding this. Some editors (including me) want to insert the comma (“DELTARUNE, Chapter 1“), some don’t (“DELTARUNE Chapter 1“), and some want to treat the chapter part as a subtitle and separate it with a colon (“DELTARUNE: Chapter 1“).
The album covers mostly look like this (the logo of DELTARUNE is in all lower case, but always appears fully capitalized in text):
The question is: Do the series numbering guidelines apply in this case? Should there be a comma inserted in “DELTARUNE, Chapter 1“ etc., despite it not appearing in any official sources?