Board Thread:Suggestions forum/@comment-26767096-20160214014845

Here's a nice nifty feature, that I'm quite sure isn't impossible: Messages to other players. The base items are quills and scrolls. Scrolls are made of paper in an ordinary crafting table, and quills are made of feathers and ink in a crafting table. A quill must be in the hotbar to put a message on the scroll. Now, here are some ways for the message to travel:

Through the Sea - You can put your scroll in a bottle, saving the scroll's contents. You can then right click on any water block in an ocean biome to send it. Then, any player at or near an ocean biome will recieve a message stating a message in a bottle has arrived, and you can find it as a block washed up on the shore. You break the block to get the scroll, and then you can read it. I will note, however, that if you don't specify the name of the player in the scroll, the message will go to a random player.

Through the Birds - Three new birds should be introduced: Hawks, Falcons, and Eagles. They can all be used to deliver messages. You can tame these birds by giving them fish or bread. Then, you can right click them with your scroll to attach it to their feet, taking one string from your inventory. The player the scroll is adressed to will get a message stating that a carrier bird has arrived, and the aforementioned bird will spawn within 10 blocks of the player, and proceed to stop at that player's feet. The letter can then be picked up and read. Once again, you must specify the player in the scroll.

TL;DR: You should be able to craft scrolls which let you send messages through both the sea and through different birds. 