How are they used?
While there are different types of Papan Turais, marking genealogies, introduction of technologies such as iron, or journeys.
But it seems like they are used by Lemambangs which are chanters/bards/priests to assist in their chanting rituals.
This is from "Borneo Writing" by T Harrison which also provides the most information I can find online about this (which I get most of my unlinked info from too), and this particular Papan Turai is used during the wake rites on the night of the death.
" to perform the long dirge, sabak, initially tracing and thereby, if properly executed, insuring the journey of (the spirit of) the dead one."
What is really interesting is that it's not actually a script, the pictographs are actually used as a reference for the chanter to recite a phrase that they would have memorized.
In this Papan Turai, the chanter is literally chanting of a journey to assist the newly departed, for instance the first pictograph signifies the start of the journey, a long house.
"This is the old site of a long-house, whence the journey to the other world begins ~ An old house site is overgrown with rembai trees, their flowers hanging like fan palms. An old house site is overgrown with durian trees, their fruits hanging like gongs. An old house site is overgrown with isu durians, the fruits like bachelor pig-tailed monkeys hanging upside down. An old house site is overgrown with mangosteen, the fruits like shamans' magical boxes".
and towards the end of the first board, the travels goes to various mountains of different peaks, and then journey goes through a series of lands of people who have died, seperating by how they died, death by pig traps, falling from trees, childbirth, etc.
And eventually reaching a family room in the other world.
"Step up the cut-notched ladder, hands holding the upside-down bamboo rails. A communal verandah is reached, decorated with sana jawa mats whose sides have been beautifully plaited. Go into this fine family room, crowded with jars showing swallows (in flight)".
The paper also notes that this might not be a full chant and some latter bits have been lost to the chanter.
When did this trace back to?
The paper above suggests that this form of writing predates 1500s, but not much is known about it, it took the community to know the writer for about 30 years before they showed the papan turai to him.
He notes about how secretive they are about it.
"these written records are deeply bound up with and guarded by pagan rites, semi-secret crafts and specific initiations; accentuated by a justified feeling that any native method of record appears (superficially) inferior to the European's and is likely to be ridiculed by the white skins."
And here's a mention of papan turais being commonly used by Lemambangs in the 1950s in Sarawak museum Journal.
But these and some academic papers/books on Google books are all the credible sources I am able to find! The dearth of information is remarkable.
1. Borneo is really really complicated! I've been casually reading about Sabah and Sarawak for a while and I can say I have near zero grasp of the narratives. On top of a lack of recorded history, lack of research available, the thousands of tribes(sometimes arbitrarily grouped together), there are also layers of complications from history wrongly naming different groups(like Ibans mistakenly being Sea Dayak)
2. The same paper also notes that there are other types of communication systems for short term information.
"including knots, twigs, vines and leaf designs of which elaborate system exists, even among the remotest nomadic Punan."