A service letter is a special variant of letter that has a "meaning" to it.
Can be sealed, mailed or placed on a wall.
Cannot be tattered and copying it will produce a regular letter.
Obtaining
Service Letters can be obtained by crafting a letter and quill with specific items.
Usage
Usage of service letter is mostly identical to a regular letter, apart from not being tatterable.
Sending
Main advantage of a service letter is its ability to convey player intent to the game systems, which can "read" the letter and produce a proper reply or action.
Currently, only Cloud Depository works with service letters, though they can be useful for player created addons and datapacks.
