For the 12/17 playtest packet:
The Classes document, under the cleric section, specifically states that unless a diety entry indicates otherwise, Clerics actually have no special armor or shield proficiencies.
Two Dieties, Lightbringer and Arcanist, list no special armor or shield proficiencies. It therefore follows that Lighbringer Clerics and Arcanist clerics are unable to use armor or shields. Indeed, neither equipment list for these clerics includes any armor or shield.
However, the playtest pre-gens have a human cleric who is a Lightbringer cleric, utilizing Studded Leather Armor (medium armor).
So, which is incorrect?