So I went to the Wikipedia entry for naproxen.
I looked at the pictorial representation, and couldn’t figure out what that part that kind of looks like a slowly widening radio wave is supposed to mean.
For organic molecules, dashed lines indicate the bond is going into the plane of the paper.
A solid line would indicate that the bond is coming out of the paper.
(Warning: I am slightly intoxicated. Hopefully, some one will back me up on this.)
IUPAC agrees with Kid_A
A solid line doesn’t indicate that the bond is coming out of the paper, it is the indication that the bond is ON the paper. There is an unlabelled hydrogen at that location of the Naproxen molecule, and it is coming out of the paper. If you were to draw it, you would draw a wedge shape (like a triangle). Some people fill in the wedge to make it “bold” others just simply draw the wedge (that’s what I do).
So the “radio waves”, I was taught to refer to them as “dashes”, indicate a CH3, oriented “behind” the plane of the paper. Both the double ring structure and the carboxylic acid (COOH) are laid flat against the paper, and there is an undrawn H popping out towards you.