breather

Hi, I need help with the fuel tank filler cap breather system. I previously thought I had an oil leak, as there were small puddles on the ground under centre stand. Now looks like this deposit is coming from the fuel tank breather pipe. In warm weather fumes can be seen coming from the pipe...

Ok, I may be a noob to bikes, but not to engines. Should I be concerned about this? I realize that there are several tubes that exit at this location, and that from what I can see in the service manual, none of them are a crankcase breather tube. If I've missed something, let me know.