[wyclif]

It's interesting how the first one looks like a triquetra. John Bonham (of Led Zeppelin) would have no doubt been pleased.

[zorpner]

It's a set of Borromean rings, a personal favorite "knot" (really a braid) of mine and a remarkably common occurrence in iconography once you start looking for them: https://en.wikipedia.org/wiki/Borromean_rings