Nsibidi

From the Wikipedia page 
Nsibidi (also known as nsibiri, nchibiddi or nchibiddy) is a system of symbols indigenous to what is now southeastern Nigeria that is apparently an ideographic script, though there have been suggestions that it includes logographic elements. The symbols are at least several centuries old—early forms appeared on excavated pottery as well as what are most likely ceramic stools and headrests from the Calabar region, with a range of dates from 400 to 1400 CE.
There are thousands of nsibidi symbols, of which over 500 have been recorded. They were once taught in a school to children. Many of the signs deal with love affairs; those that deal with warfare and the sacred are kept secret. Nsibidi is used on wall designs, calabashes, metals (such as bronze), leaves, swords, and tattoos. It is primarily used by the Ekpe leopard secret society (also known as Ngbe or Egbo), which is found across Cross River among the Ekoi, Efik, Igbo people, and other nearby peoples.
Outside knowledge of nsibidi came in 1904 when T. D. Maxwell noticed the symbols. Before the British colonisation of the area, nsibidi was divided into a sacred version and a public, more decorative version which could be used by women. Aspects of colonisation such as Western education and Christian doctrine drastically reduced the number of nsibidi-literate people, leaving the secret society members as some of the last literate in the symbols. Nsibidi was and is still a means of transmitting Ekpe symbolism. Nsibidi was transported to Cuba and Haiti via the Atlantic slave trade, where it developed into the anaforuana and veve symbols.
There is various coverage eg and 
Category:Undeciphered writing systems