The main title (before the colon - no subtitles) should include a seven-letter word/name..or seven characters if the language of the book doesn't use a Latin/Roman alphabet. (The language of title should match the language of the text.)
Any type of release is acceptable.
CUTTING for Stone
Prince BERTRAM the Bad
Do Not Say We Have NOTHING
Also valid: the number seven in the title (in the language of the text) including 7 or VII or 七 or...
Seventh & seventeen are ok. Or 7th Avenue, or 1776, because the intent is to have a seven in there.
No embedded VII though, so Henry VIII would not work (after all, that's meant to be eight.)
Ask if you have questions; no need to sign up. Go ahead and post here once it's July where you are.
Additional notes: words/names with apostrophes (couldn't, Poirot's) which add up to seven letters are fine.