varnishlog output column meaning

[Tung Nguyen]

Hey guys,

In the the varnishlog output

https://gist.github.com/8b163cc29fbd5e3141f6

Where can I find out more info on what the columns mean,
So what does the 7 vs 10 mean in the first column?
What does the b vs c mean in the second column?

 7 VCL_return   c pass
10 BackendOpen  b default 127.0.0.1 57141 0.0.0.0 3000
 7 Backend      c 10 default default
10 TxRequest    b HEAD

Thanks in advance for any responses,
Tung