Lingering Potion

Lingering potions are variants of potions that can be thrown to leave areas with status effects which linger on the ground.

Usage
Lingering potions are thrown, like splash potions, by them. On impact they explode, creating a cloud. The cloud is made of the potion particles corresponding to the potion that was thrown.

The cloud starts with a radius of 3 blocks, decreasing to 0 over the course of 30 seconds. During the cloud's existence, any player or mob that walks into it after the first second will get the corresponding status effect; this decreases the radius by a $1/2$ block immediately, causing the cloud to disappear more quickly.

For effects with duration, the duration applied by the cloud is $1/4$ that of the corresponding potion. For effects without duration such as Healing or Harming, the potency of the effect is $1/2$ that of the corresponding potion.

Lingering Potions can also be thrown out of dispensers just like splash potions.

Thrown potion
Lingering potions when thrown have entity data which define various properties of the entity. Their entity ID is. What makes it a lingering potion as opposed to a splash potion is that their  tag stores a   item.

Area effect cloud
The cloud that is created when lingering potions are thrown – and when creepers with potion effects explode – is an entity, which has entity data that defines the properties of the entity.

History
Verweilender Trank Potion persistante Оседающие зелья 滞留药水