I don't know about the other one but we had a topic about the Nameless seal on our Facebook group for new members, Project Oistar. I'm sure Frater Alysyrose won't mind if I quote him:
"I first put this in 'The Assault On Reality: A Field Manual' on the 'Underground Citizens Association' page. It's been used alongside the Media Magician concept as well.I created the symbol itself, or discovered it depending on how you look at it, though it seems like such an obvious pairing that I'm surprised it wasn't super-popular even then.Maybe some corner of the world uses a similar design, I don't know. The symbolism is obvious, union of dualities within a singular whole etc.and it can be carried on from there. Though there is a certain unwanted Ellis possession story in sigillum where the Nameless sigil played an effective part in banishing."
Other people said it was 'infinite and void in a bubble' and a neutralizer which increases focus by neutralizing everything.