Billiards / Cue Sports types

[danieldegroot2]

Pool, snooker, etc. may be tagged as subtypes of billiards (cue sports)
https://taginfo.openstreetmap.org/search?q=billiards%3A#keys
though there is not much use of this tagging.
(sidenote: some can be played on the same table so it may be unclear if the balls are not present at the table itself)

See also https://en.wikipedia.org/wiki/Category:Cue_sports