How to add special characters like emojis and accent marks using your computer's keyboard

You can add special characters on a PC or Mac computer by using keyboard shortcuts or accessing a pop-up window.
Hackaday

Building Up Unicode Characters One Bit At A Time

The range of characters that can be represented by Unicode is truly bewildering. If there’s a symbol that was ever used to represent a sound or a concept anywhere in the world, chances are pretty good ...
Ars Technica

Any idea why I'm getting the wrong unicode characters?

When I hold down the Alt key and press +00C6, I should get this symbol Æ (which I inserted from character map), but instead I get this symbol ♠ (which I typed in directly).<BR><BR>Any idea why I'm ...