In entry #2 I like the mark. What if the outside edges were closer to a square, but still read like a C and a D? I like the font that you selected. In entry #1, if you used the font from entry 2 and added some color I would like it more. I also would like if you took out the breaks in the corners of the outside line that break the corner at a 45 degree angle. If you removed them completely or moved them to the middle of the vertical portion.
Hi, sorry for writing until now, and thanks for your comments, i have uploaded another variation just for testing, if you want any changes or submit other ideas, i will be glad to do it.
In entry #173, could you add a thin vertical line that goes in between the blue and the grey and cuts through the green rectangle. It could symbolize the river that goes through my city. I like the arrangement.