Minecraft wiki entry for Multiplayer, associated text: Chat history - A small scroll bar is on the side of the chat bar. The player can also scroll using the mouse wheel or PgUp and PgDn. The last 100 chat messages are stored. Holding down ⇧ Left Shift or ⇧ Right Shift and attempting to scroll up or down slows down scrolling.
The player can view their own recently sent messages by pressing the ↑ and ↓ keys while typing.
Clickable links can be pasted in chat.
The ability to copy (Ctrl + C) & paste (Ctrl + V) in chat (⌘ Cmd is used as a replacement for Ctrl on some Macs). ⇧ Shift + ↑, ↓, ←, → selects text for the player.
Font styling: the section symbol (§) allows players to change the style of the text. See the list of formatting codes for further details.
Note: the section symbol cannot be typed in vanilla clients because they are restricted characters. Even in single player, if § is pasted and posted in chat, the player who sent it is automatically kicked with an "Illegal characters in chat" message, and a server-side disconnect.endOfStream error is given. Even in single player, the only available button opens the server selection screen.
On Bedrock Edition, certain emojis appear as icons in-game, such as the hunger and armor icons[1]. Other emojis and unknown character show up as a ? (question mark.)