CrisGear the acronyms,mostly from XI but some also in XIV,are as follows:
LS - linkshell
FC - Free Company
Gearscore - you can wear it @50 but it says lv90
LB1 - Limit break 1 (quest to allow you to level beyond the first lv cap)
AF - Artifact (gear - same exists in XIV)
ToAU - Treasures of Aht Urgan (XI expansion)
WHM - White Mage
NIN - Ninja
DF - Duty Finder