Hello!
A search on the Banknote Database website (which is also an excellent source of banknote data, in addition to Numista, of course 😎) gives us the following information.
https://banknotedb.com/1-000-livres-2016-k228
"Banque du Liban (BDL), the central bank of Lebanon has launched a research project aiming at studying the evolution of a banknote with time and at measuring its durability.
The project consists of putting into circulation 11 million banknotes of the lowest denomination (1000 LBP) along with the existing banknotes in circulation from the mentioned denomination. The trial banknotes, have the same design of the banknotes in circulations, belongs to 11 groups representing several substrates, varnishing and intaglio printing."
Collectors identified notes from serial number range "K228" as hybrid substrate and the conclusion was, that notes from K220-K229 probably belong to the project. However this covers only 10 million notes. so at least 1 further variety needs to be identified (K219 or K230?)
Except for the K228 which is clearly printed on hybrid substrate, it is very difficult to identify the exact type of substrate that was used for each "prefix" from K220- K229. However it is believed that they are all different and thus mark 10 new varieties (the 11th to be confirmed).
For more information, see "Banknote Substrate Durability: A live circulation comparative study" by Georges Chalhoub and Mazen Hamdan.
I adjusted the line to Serie K228 and added the replacement variety line K99, which is the banknote from @ceh2019 . =)
Further research is welcome in this topic!
Regards,
Vladimir.