Fu (Chinese: 符),Shenfu (Chinese: 神符) which they believed functioned as summons or instructions to deities, spirits, or as tools of exorcism, as medicinal potions for ailments. It is believed by Taoists that in the past the ability to write Shenfu had been once decreed by their deities to authorized priests or daoshi.
Lu (Chinese: 籙) is a register and compilation of the membership of the daoshi as well as the skills they were able to use.
These practitioners are also called Fulu Pai (Chinese: 符籙派) or the Fulu Sect made up of daoshi from different schools or offshoots of Taojia.
Fu script was also used on Taoist coin talismans (many of which resemble cash coins), many of these talismans haven't been deciphered yet but a specimen where Fu was used next to what is believed to be their equivalent Chinese characters exists. On rare occasions Taoist Fu writing has also been found on Buddhist numismatic charms and amulets. Most of these coin talismans that feature Fu writings request Lei Gong to protect its carriers from evil spirits and misfortune.