Friendship is Aura tagged "Alternate Universe" as of the season 4 finale · 9:49am May 11th, 2014
Luna's canon transformation into Nightmare Moon in comparison to how I did it in FiA was one thing, but I can't ignore the information given to us in these latest episodes. As always, though, this will not impact the story, since it takes place between season 2 and season 3. If anything, I might write a bonus chapter in the future about how the events would've unfolded if Lucario had been present, but not right now. Loved the season finale, and I wish all of you well in waiting for season 5. The fourth pony drought is now upon us, people. Stay strong!
Edit: Apparently the AU tag requires more dramatic changes to the setting than that. I'll keep it away for now until I can make heads and tails about it properly.
Season finale needed more Spike
but other than that
it was pretty good
You know, if your story is posted before the show that would make it AU airs, you don't have to tag it AU. Also, AU is meant for when that changes the world greatly. For example, my story, Chaotic Harmony, deviates from the show quite a bit; Twilight's parents died when she was very young and was adopted by Celestia, Rainbow Dash has an egg-head unicorn professor for a sister, Fluttershy is 1/4 dragon, and several others. This story, however is not AU because those can either be explained away (Fluttershy doesn't tell ponies her ancestor, for example) or they don't affect the story enough to consider (Twilight's not the main focus of the story).
2100593 Perhaps you're right. It's hard to make out where the line is drawn for when a story should be tagged AU or not. But I made a double check on the FAQ page, and it seems to support your reasoning. I'll keep the AU tag away for now until I'm really sure. Thanks for the heads-up.
2100784 The main reason I felt the need to bring that up is that a lot of people avoid AU. If they see the AU tag, they might assume this is a Pokemon fic, but with pony's playing the role of the humans.