Shield Proficiency with Feats

[JackPhoenix]

A part of design that is never explicitly stated but is heavily implied with each instance is that a character should have Medium Armor proficiency to have proficiency with Shields. To my knowledge, there is no way to get shield proficiency without also getting medium armor proficiency, and I'm pretty sure its intentional.

Multiclassing into barbarian gives shield proficiency, but no armor proficiency.