I see most 'circle' tags are like the Wiki says, for something like a huge moon in the background. i.e. The well-known Sailor Moon pose. Also, circular backgrounds of other kinds.
I see that circle_(marking) makes sense as it's for stuff like the Umbreon's gold circle on their body.
I see triangle_(shape) as a disambiguation (I guess that's what it's called - not checked history of the tag), but no circle_(shape). Is it sensible to create a tag called circle_(shape), to be consistent, just for stuff like the single-post example of circle_(shape)? post #3679218
Or should it not get tagged, or get tagged as one of the other 2?

Thanks for help! :)

:edit: Also looking at squares. Not sure if those basic shapes should be suffixed with _(shape). Square seems to be used like circle (big rectangle in background for example), but also for square shapes?