They just mean that the path continues, and i was unable to map any further. They were the OSM version of an ellipsis.

The alignment =a/b/c are for searching and auto squaring up in Josm when adding new data. Everything which is squared up together is tagged the same. I will take a look at the data when I have some time, but try looking at it against the Bing aerial images and it should be apparent what it is.

Anything blank is unknown, or unfinished, or both, and is awaiting further editing. If you can be more specific I'll take a look.