Class that has a Book out when in Combat / Weapons drawn

From time to time, and particularly during the Winter Veil jumping puzzle event, I see characters who have an open book floating next to them. I've tried to figure out which class this is or whether this is some special effect like Winter's Presence and have utterly failed.

I'm hoping someone can help because it's driving me a bit crazy that I can't find an answer.

Thank you!

What you're seeing is likely the legendary weapon "The Binding of Ipos".It's a focus and can be used by any profession that can use a focus.

Ipos also remains open while mounted, so if you've seen someone whiz by on a Raptor with an open book hovering in front of them, there ya go.

Ah. Thank you!