Only thieves guild members will know what I'm talking about (and maybe not every one of them if you missed it).

Are shadowmarks useful? Are they easy to spot?

So far I've only found one in Whiterun and it was even before I knew what it was all about. I find the concept of shadowmarks very clever so I hope they become a part of my gameplay.

I've found a few now, always keep the book with me, but I haven't really found anything useful from them :confused:

I can see them and I have no idea what they mean.

Yes they are everywhere, yes they are easy to spot, but they are literaly obvious. Empty square of some random hut, square with horizontal lines on the smith shop. I would have never guessed!

P.S. Fun thing I guessed their meaning before I even found the Thieves guild and the respective book. Beggars used same markings before and today people mark up buildings if they have WiFi available.

What is this then? I play as a thief??

Why not hints and spoilers?

They are fairly easy to spot. Usually they are carved next to a door. They usually tell you that there is either plenty, or no loot, potential danger inside, etc.
I saw a documentary recently about real-live homeless people that actually use similar symbols in grafitti to warn others about gang turf or other information.

If you don't understand them, go to the thieves guild in riften and find a book named shadowmarks.

Good question, but you clicked the link yourself, nobody forced you.

I've finished Thieves guild and know about it, I just thought about other people..

Not sure they have been implemented correctly. I know I've been robbing some houses that are supposed to have loot in them, but unless you count a horker loaf and 4 potatoes in a barrel as loot, there was nothing there.