Testing1: Mechanics

Harvest: To harvest, remove an essence counter from a land you control or sacrifice a land. Used on 0 cards:

Harvest is an additional cost that allows you to remove Essence counters from your lands or sacrifice those lands to get additional benefits.

Essence counters: A land with an essence counter on it has " {t}

: Add one mana of that essence counter's color." Gold essence counters are all colors. Used on 0 cards:

Essence counters represent the land's raw mana essence that can be harvested by other beings to power up their spells. If a land gains a blue essence counter, it can now tap to add blue mana in addition to all its other abilities, and other mechanics like "harvest" can remove those counters for different benefits.

In card text or details pages, write the mechanic's code name (playtest name) between square brackets, like "[Crittercast]", "[Bushido 1]" or "[Delay 4 {2}{R}{R}]". It will be expanded to the mechanic's name plus reminder text, such as "Suspend 4 – {2} {r} {r} . (Rather than cast this spell from your hand,...)"
To expand a mechanic's name but not its reminder text, include parentheses at the end of the square brackets: "[Crittercast()]", "[Delay 9 {R}()]".