Minecraft wiki entry for Flattening, associated text: CollarColor of Wolves has the colors in the opposite order for consistency.
carried and carriedData of Endermen merged into carriedBlockState.[NBT note 1]
inTile and inData of Arrows and Spectral Arrows merged into inBlockState.[NBT note 1]
DisplayTile and DisplayData of Minecarts merged into DisplayState.[NBT note 1]
Block and Data of Falling Blocks merged into BlockState.[NBT note 1]
ParticleParams1 and ParticleParams2 from Area Effect Clouds removed, merged with Particle (same formatting as in the command).