diff --git a/tasks.md b/tasks.md
index 5e54591..c934488 100644
--- a/tasks.md
+++ b/tasks.md
@@ -7,6 +7,23 @@ You can try connect IRC server with
 ```bash
 nc localhost <port>
 ```
+---
+
+### User
+
+Represents a connected IRC client.
+
+| Attribute       | Type     | Description                                    |
+|-----------------|----------|------------------------------------------------|
+| `fd`            | `int`    | TCP s-ocket file descriptor                    |
+| `nick`          | `string` | IRC nickname                                   |
+| `username`      | `string` | Username                                       |
+| `realname`      | `string` | Real name                                      |
+| `buffer`        | `string` | Incoming data buffer, accumulates until `\r\n` |
+| `authenticated` | `bool`   | `true` after correct `PASS`                    |
+| `registered`    | `bool`   | `true` after `NICK` + `USER` received          |
+
+**Registration flow:** `PASS` → authenticated → `NICK` + `USER` → registered → client ready
 
 ---