Lettering in a rock?

[vancliff]

I found another interesting object in Sol 188. Apart from looking like something with a round wheel, over the object there are like letters. They can be seen clearly.

Here is the picture:

[Marsrocks]

Vancliff, there are some interesting shapes in this image, but I'm not sure which one you are seeing. Can you circle the wheel-like object for me?

[vancliff]

Here are the marks for what i am seeing