Description of Pound Net Sites

How do I read these pound net sites?
What do the red dots mean?

Two RED dots

(This represents a single pound net with no coordinate displayed)

Pound Net with 2 red dots

Three RED dots

(This represents a double-ender with no coordinate displayed)

Pound Net with 3 red dots

 

For further information, email Chris Jones or call 410-260-8343.