We've been using these markers in a standardized way for recently ranked maps such as https://osu.ppy.sh/beatmapsets/995098#osu/2081395 and https://osu.ppy.sh/beatmapsets/984684#osu/2060305, but there are no rules about it in the RC. To avoid useless discussions and misunderstandings, I think rules about these markers should be added. This doesn't actually change anything, it just makes the unwritten rules official.
It could be something like this:
It could be something like this:
If a song has been edited to have a higher tempo, use a (Speed Up Ver.) marker at the end of the current title string. If there is an existing 'Speed Up Ver' marker in the title, the (Speed Up Ver.) marker would replace it. For songs of the genres Techno, Trance, Dance, Eurodance, Hands Up, Jumpstyle and Hardstyle, use (Nightcore Mix) instead.