By the way, I'll create the Railgun manga special chapter for preview or announcement soon, but I'm not sure what the title should be. For example, Endymion preview chapter released between chapter 56 and 57.
- "Toaru Kagaku no Railgun Manga Chapter 056.5"
"Toaru Kagaku no Railgun Manga Special Chapter: Miracle of Endymion Preview"
The former is simple, but most of preview/announcement chapter isn't part of specific story arcs. The latter is glanceable, but some chapter may have really long name and it does not fit to "chapter title consistency".