How do you add tags to your posts?
You write @ and then the name of who you want to tag
And if you mean by adding tags like "dressage", "eventing" and so to your posts, then go to the bottom of your first post and you'll see something like "Enter tags here, between 3 and 15 characters each." in pale gray letters riiiight under your text box.
I dont have that box with "enter tags".
You need to be composing or editing the first post of a topic, since it tags the whole topic instead of just your post. If you don't see it you might try changing your view of your post by clicking the dark bubble with an arrow in it in the top left of the composition viewer.
The bubble with the area showed the tag line, thank you!