It has been found in more than one location. Notice how the palindrome "works" when reading the words left to right, and also up to down. The middle word "tenet" forms a cross. So, some have found Christian connotations. I have never seen an agreed upon translation.
Didn't Dan Brown use yours in The DaVinci Code, Z?
He could have, Geoff. Even though I read his book, I do not remember much more than a sense of outrage at his bad writing and the bare outline of the plot. I read another of his novels, about cryptography and computers, IIRC, and it was even worse. One of the authors of the "historical" book on Jesus and his French bloodline (Holy Blood, Holy Grail) tried to sue Brown for stealing the plot of his book from them, but a judge pointed out that you can only steal fictional plots, not history.
I tried to read a Dan Brown once. He joined the very short list of authors who have written a novel that I have failed to finish reading.* I thought the writing was just about as bad as I have ever come across in a published work.
As for palindromes, one given in the Wikipedia entry on the subject is
"Doc, note: I dissent. A fast never prevents a fatness. I diet on cod""
(*I subsequently failed to start all of his other novels )
"No man but a blockhead ever wrote except for money." Samuel Johnson.
Kinnikinnik is the largest one-word palindrome that I know of, though it is more often spelled Kinnikinnick. Wordcrafter pointed that out on April 28, 2004.
Thanks for the palindromes, all. I particularly liked the Latin square, and Arnie's last one is mind blowing, although it doesn't make all that much sense to me.
I noticed that the capital letters A H I M O T U V W X & Y are all letters that are the same backwards (in a mirror) as forwards. I first noticed that "TOYOTA" is one letter short from being read the exact same in the mirror as from the front "ATOYOTA" would read the same in a mirror. It is easy to find a lot of three-letter words that would fit that bill and some like "TOOT" for four-letter words. I bet a sharp person could find a longer word that works both ways.