• Where people used it/developed it at what time

According to AncientAfricanHistory.com, Nsibidi is believed to have been in use since approximately 5000 BCE, though the oldest extant examples trace it to around 2000 BCE. It is an ancient symbolic script used by the Ejagham or Ekoi people, who spread it to Ibibios, Efiks and Igbos, in modern day Nigeria, Cameroon, and Chad.

• what artifacts show its use

Nsibidi appears on clothing, pottery, skin (tattoos), and on houses. It was also used to keep records of events such as trials. Nsibidi is split into 2 variants- common and sacred, across thousands of symbols. The common use include women’s textiles and tattoos for both sexes. The sacred sort was used by secret male societies, such as the Nigerian Leopard Society, and by the government of the tribes. Its most ancient uses were found on pottery starting in the early 1900s.

• what languages use the script (for example, Ajami is written in many languages (Wollof, Kiswahili, Hausa, and many more!)

Nsibidi is used for Nigerian, Efik-Ibibio, Igbo, and Jagham.

• and if you are able, its significance to users and to world heritage

Nsibidi is the earliest of the West Africa languages we have found below the Sahara. Though East Africa is known to have had writing back to the same period and farther, West Africa is generally not acknowledged to have had writing in the non-Saharan countries, leading to the reference to Blackest Africa.

Nnedi Okorafor has brought attention to the script and its languages in her Nsibidi Script trilogy.