After you speak to Cid in his solar in CH8, you can go over and examine the letter sitting on his desk. Unlike a lot of the documents floating about the hideaway, this one’s very easily legible. The text is as follows.
Interestingly, it would seem Valisthean contains a reduplicator character that doesn’t appear on Shirleigh’s “LETTERS OF THE REALME” chart in the new hideaway—i.e. if you have two of the same letter, you write the letter once, followed by the reduplicator. This is the first time I’m noticing it, so it’s possible it’s shorthand and not used in official writing.