Well, I only clicked on a couple, but, they seemed to have a short explaination to their use when clicked. I don't think they all do, though.
So, that's funny. You saw the sigil in a magic book and liked it. Almost odd how you are now in a fairly good conversation on that very subject
now.
So far, what I've read says there are a few ways to generate a sigil. In my
personal experiences with sigils, I invented the meanings behind
them. I refered to them as runes though. Rune magic is more of a scrying device, as I understand it, with no effect generated but divining the fates
and futures.
Cuhail