symbols used in construction plans

invalid@example.com (Messerschmitt), Messerschmitt
Mon, 23 Nov 2015 19:55:23 +0000
naval

Good evening, everyone.
I am studying the designs of the construction plans of a small ship. the hull is geometrically very simple, as it consists only of plain surfaces or simple curvature.
I would like to know if I am correctly interpreting some symbols that I found:

- where the profile used as a current changes $.

- on the horse of the lines indicating a variation of thickness of the strip there is a |=|.

- the lines that indicate a edge between two sheets (for example, at...