Minecraft wiki entry for Development_versions, associated text: Do not show off particles.
They do not have inventory sprites.
Added obtainable status effects:
Regeneration, which increases health slowly.
Obtained after eating a golden apple.
Hunger, which decreases the hunger bar.
Obtained after eating a rotten flesh or a raw chicken.
Poison, which hurts the player.
Obtained when being hurt by a cave spider.
Added unobtainable status effects, but are functional:
Speed, Slowness, Haste, Mining Fatigue, Instant Health, Instant Damage, Water Breathing and Nausea.
Added unobtainable and nonfunctional status effects:
Strength, Weakness, Jump Boost, Resistance, Fire Resistance, Invisibility, Blindness and Night Vision.