What is the proper preposition following 'appendix'?
Solution 1:
I wouldn't object to appendix for, appendix of, appendix behind, appendix following, and so on, but by the NGram, appendix to is favored by a wide margin:
There may be some false hits here as appendix can also refer to an internal organ, among other things, but since those uses would be overwhelmingly appendix of (e.g. The appendix of a ruminant, unlike the appendix of an ape, is a true appendix, or cecum), the point stands.