When you enter a tag, it automatically turns spaces into dashes. But many pre-populated suggestion tags have underscores already. Is that because the data was brought in from e621 or something? Might want to have spaces auto-convert into undescores instead. That would be more in line with other sites' tagging / filenaming conventions.
If you decide to do this, better do it soon, because the more art people upload and tag, the more dual tags there will be. Since all the spaces are being auto-converted to dashes, it's going to become a big mess soon.
If you decide not to do this, I suggest eliminating underscores all together and converting all the pre-populated tag suggestions into ones with dashes.
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