A couple of days ago I proposed runes of Mordor based on Angerthas Moria which I called Angerthas Mordor but a comment by OneBehindTheHair pointed out that even though Orc might be using Cirth they were, at least at the time of the War of the Ring, not used by Mordor
I’m not sure if Mordor actually used any variation of the Angerthas. The Uruk-hai of Isengard wore an Angerthas ‘S’ rune on their helmets, which is the only known case of Orcs/Orcish societies using Elf runes.
“‘S is for Sauron,’ said Gimli. ‘That is easy to read’
‘Nay!’ said Legolas. ‘Sauron does not use the Elf-runes.’”
-The Departure of Boromir, The Two Towers
Still I think it is fitting that there are some kind of Mordor runes. Tolkien mentions runes in association with orcs who most probably comes from Mordor in The Two Tower, The Black Gate is Closed
They had not come very far from the road, and yet even in so short a space they had seen scars of the old wars, and the newer wounds made by the Orcs and other foul servants of the Dark Lord: a pit of uncovered filth and refuse; trees hewn down wantonly and left to die, with evil runes or the fell sign of the Eye cut in rude strokes on their bark.
These “runes” could of course be the Mâshur signs so there is no need for proper runes. And so I have designed runes of Mordor derived from Mâshur, still named Kirkhi. The diffence between Mâshur and Kirhki is the tools they are used to write with. Mâshur is written with a pencil or carved in stone. Runes are designed for being carved in wood – that is the purpose of the 45˚ lines, horisontal lines merge with year rings. I imagine a development scenario were Sauron at first uses Tengwar to write the Black Speech which soon is transformed into Mâshur. The servants of Sauron already know about runes and a rune variant of Mâshur is developed. The universal word for rune in Middle Earth is Sindarin certh, (plural cirth) wich by the twisting of Orcs becomes kirkh (the uvular r shifts the dental th in front of the mouth to velar kh in the back).
Note: On some of the signs used in the chart:
I.3 þ= th
I.4 ð = dh
III.3 ʃ = sh
III.4 ж = zh
I wonder why I in IV.2 didn’t use ɣ for gh. And IV.4 r is of course IPA ʀ