[FFmpeg-user] Report file explanation

[jacky]

HI

I try to undestand details stored in the report file created by FFMPEG
  -report from the command line (libx264)
is there a link where I can read and undestand what these differents 
values means
like NAL (I think I found it) , Poc, QP , P,   SKIP ...
is there any glossary somewhere ?
ffmpeg is a great tool , sometime too much complex for newbee as I
thanks a lot for inputs
jacky