The character who you are adding an arrangement to must have the amount of blocks the character mainly has in NFG.
The arrangement should last at least more than five frames.
The entire arrangement should be visible; 3D arrangements should just have the front visible.
Separate or off-grid arrangements should be intentionally made.
If the character has a new design - arrangements of that new design only: for example, Tiberadog, Saucer, and Lantern made many arrangements in their old designs, but users removed them and replaced with their new designs.
How to read the codes
\ means go right a layer
U means all blocks are higher.
L means all blocks are lower.
S means the blocks in that row are completely separated.
[o (parentheses)] means that blocks are skipped, and the parantheses indicate how many blocks are skipped.