@quest There's no standard convention on which hashtags to use. When you type in a toot and have to ponder which hashtag spelling to use, you could in the meantime search for those hashtags and see which one(s) are the most common to join in with the crowd. 'Tis what I do too. Most common style I have seen are PascalCaseHashtags. (And also recommended so blind people with screen readers would be able to interpret this correctly instead of one very long word that becomes undecipherable).