2- THE ALPHABET THEORY
This one is probably more of a coincidence than something purposefully done by Oda, but it’s fun to mention. The gist of it is if you put the alphabet into 13 sets of 2 you get an initial of a Straw Hat member.
AB – Brook
CD – Chopper
EF – Franky
GH – ?
IJ – Jinbe
KL – Luffy
MN – Nami
OP –
QR – Robin
ST – Sanji
UV – Usopp
WX –
YZ – Zoro
With 3 remaining there’s a character that begins with G/H, a character than begins with O/P, and a character that begins with W/X. However, it doesn’t have to be a real name as Franky’s name is Cutty Flam. The theory is that O/P could be Yamato as they go by Oden. W/X could be Wanda but this is more a fun theory/coincidence.