Unchained Monk Multiclassing 2 question 2016

[Jeff Clem]

I tried but couldn't find the answers.
Unchained Monks cannot multiclass in monk(Archetypes), this I know.
Can they multiclass in others classes(prestige,Archetypes etc.)
Is there a penalty for leaving the Unchained Monk? Thanks for your input.

[Derklord]

It's a normal class - you can multiclass into anything but ordinary monk.

[Chess Pwn]

Archetypes aren't multiclassing. UMonk just didn't have any archetypes. But you can multiclass them with anything but original monk.

[David knott 242]

Also, there have been some archetypes published since Pathfinder Unchained that can be taken by the Unchained Monk.