I was just listening to Jehtro Tull's Thick as a Brick on Spotify and I noticed that the album cover had a red square in the upper red corner in which you can see the band name. See the image for a more visual approach to what I mean:
Now I'm quite sure that my LP version is exactly the same but with a black corner instead of a red one. I'm not at home right now so I can't take a picture, but I can't seem to find any evidence that this edition exists.
Now the question is: is this an official release?