There are two symbols on the drawing I don’t know the meaning of; first one is hexagon that goes everywhere with butt welding. Second is triangle. I would be more than happy if somebody can explain what they mean. I attached a part of a drawing so you can see what I mean.
This looks like a US Navy drawing, and both of those symbols should direct you to line items in the revisions list. Check the revision page(s) and look for the symbols and the numbers that go with them. And the hexagon next to the butt is not a welding symbol