I think a lot of these are self explanatory, so some will be marked as such. However, if you have any questions regarding any square, or if a particular book will fit anysquare, please don't hesitate to ask.
Mystery/Crime - Pretty self explanatory, though I will add true crime will definitely work on this square, too.
Fantasy/Sci-Fi/Paranormal/Urban Fantasy/Supernatural - Books containing any of the following: magic, space, time travel, aliens, ufos, parallel universes, ghosts, etc.
Published the year you were born - Self explanatory
One Word Title - Self-explanatory, but with the reminder that "The" counts as a word. ;)
Children's or YA book - Books geared towards the under 18 set.
Fanfic of at least 100k words - Self-explanatory
Comic/Graphic Novel - Self-explanatory
A Favorite Re-read - Revisit an old favorite.
Diverse Reads - Books written by POC and/or LGBTQA authors or featuring POC and/or LGBTQA characters.
Recommended by a Friend, Family Member, or Colleague - Self-explanatory, but with the reminder that we are always available to make recommendations if needed!
Published this Year - 2018
Non-Fiction - Self explanatory
Free Space - Any published book of your choice here!
A Romance - Any genre, any heat level, het, m/m, f/f, erotic, menage, whatever as long as it's classified a 'romance' it counts.
At or near the bottom of your TBR pile - That book you bought five years ago and haven't yet read? This is the square for that.
Number or Color in the Title - Self-explanatory, with the reminder that for the numbers Regular/Cardinal numbers (one, two, three, etc.) and Ordinal numbers (1st, 2nd, 3rd, etc.) count for this square. Roman numerals count too (I, II, III).
Animal on the Cover - Pretty self-explanatory, I think.
Script or Screenplay - Any published script or screenplay will work here.
TV Tie-in/Turned into a TV Show - This would be the place for any novels based on popular tv shows, or those books that have been turned into tv shows (your GoT books, your Shannara Chronicles, your Sookie Stackhouse books, etc.).
Biography/Autobiography - Self-explanatory
Poetry/Play - Pretty self-explanatory, I think?
Horror - Pretty self-explanatory, I think?
A Classic - A novel published in the past that stands the test of time.
Never Judge a Book by its Movie - If they've made a movie (no matter the quality of the movie) based on it, it's eligible for this square.
Out of Your Comfort Zone - Anything that's outside of your preferred reading genres.