Glad someone's finally interested in these. I found and deciphered quite a few a very long time ago and posted them in a few threads, I think these are all of them...
The button thing that throws statues at you in Reptile's Lair means "LIZARD", I think.
The tournament victories wall in the Portal reads "LIU KANG WILL DIR" vertically.
"TOASTY" is repeated on banners en route to Mileena in the Living Forest.
Every map when you pause has a coded message on them...
Goro's Lair and Wu Shi Academy: "DAVID SAYS BEWARE OF EVIL RAIDEN".
Portal and Evil Monastery: "DEADLY ALLIANCES AND DECEPTION RULE THIS LAND".
Living Forest: "THE SECRET UP THE TREE".
Soul Tombs: "DARE TO CHALLENGE THE MIGHTY BARAKA".
Wasteland: "HIDDEN (RUNES / WORKS) ARE OVER THIS GOD LUCK FINDING THEM".
Netherrealm: "BENEATH THE MASK OF SCORPION LIES ETERNAL PAIN".
Foundry: "HIDDEN (RUNES / WORKS) ARE OVER THIS GOD LUCK FINDING THEM".
The Wasteland and Foundry ones are more faded than the others and were harder to decipher.
Some hard-to-see banners in Level 2 of Survival Mode have some names written on them (like "DAVID" or "TONY", I think), probably that of programmers who hid them there. Other banners are just gibberish.
And that's about it.

Awesone job! Thanks.
So, here is my philosphy on what you posted. Since the Survival Mode was found in the Foundry and your messsge above states "Hidden", is that a clue now that you posted the Wastelands also says "Hidden" in the coded message?!
I bet the final secret to MKSM is in the Wastelands. Thank you.

This is the first time I've heard about this. Can someone tell me what I'm looking for? Are the symbols from a sheet in a concept art section? I'd love to help in the search for this but I never saw any words before. Please educate me guys, if you have the time.

In the Koncept Art area is a list of Outworld letters A - Z and then a page that shows symbols, I think it is either before or after the alphabet. The letters and symbols are throughout the game. Goroliath has decoded most of it, if not all of it so far.

Hey I found the symbol guide you were talking about, I don't know how I missed it before. I will keep looking though, can you provide a link to your old post that had everything revealed? I don't want to re-translate things I find if someone already has them translated. cool find once again.

hey on the primas shaolin monks guide they have writing near the maps

I saw the symbols on the maps but they are so tiny. how did you guys read them? I am curous if everything has been decoded. Is it complete goroliath?