Cap shrouds are the ones going to the top of the mast. Then you have main ones running through the spreaders and the lowers(sometimes diagonals I think).
Also, you did have a look at the old "49er owner's manual?" http://www.49er.org.uk/cms/upload_area/downloads/49er-owner-manual.pdf
Oh that is very good detail to know. Always had the knot "since one never sheets out that far anyway" but I also always worry about the mast remaining standing so anything against that is nice to know!
With a little luck we're having Julian in here soon to give the cliff notes. Until then I asked similar questions before.
Second post outlines how the 49er usually measures prebend/rake with the jib halyard.(that is where you'll get the references for)
Usually forestay is within ranges and...