Hello to everyone.  What do the marked places in the picture mean?  How can I track this in the document?

Each page of circuit has a sequence of numbers running along the bottom, cropped out of your image unfortunately. The numbers in the rectangles tell you which of these numbers at the bottom of the page to go to to find the continuation of that wire. Often but not always on a different page of the circuits.

When you get to that page/number referenced in the rectangle, you'll find another rectangle referring you back to where you just came from.

 

It's explained in this document: 

 

CFD explanations.pdf

got it, thank you very much wino. You know this job.