Is there a way to create something like a "user link", to whisper someone by clicking on his name ?
In fact, I have an addon who get player name and link when someone loot something and print it, and I wanted to be able to whisp this person just by clicking on his name.
These are specifically for local display in your own UI. Sending them in chat is a different story and the server filters these heavily to prevent faking of messages. If a link doesn't match a list of approved link types and are paired with their appropriate color codes, they'll be reverted to normal text.