Segments Data Screen Explained

Can anyone explain me all the numbers on segments data screen? 

Here is a screenshot I downloaded from the web:

My guess is: 

4:28 - timer (from start of segment)

0:40 - distance remaining

P - what does P mean? I have also seen PB, RB, ...

L s - what does L s mean?

Blue arrow - me

- 0,17 - I am 17 seconds behind P? Confused because PacePro shows - sign when I am actually ahead....

+ 0,22 - I am 22 seconds ahead L s? 

Thank you :-)