Macroing (Also known as Botting) is a third-party software or program that will automatically battle and level up your Pokemon so long as the computer is on. It's against the creed rules and could result in your account being disabled and an IP ban.
Da Man has added several security checks which will trigger whether or not the account is using a Macroing software. It works like this: If an account is battleing an NPC, then the software will simply click random moves as fast as possible. This means that if the player clicks on moves too fast, a screen will pop up. This will show two random words, which the player must input underneath. In some editions, it will show two Greek letters and a drop down list. If the player doesn't know the answer, there's a link which will lead to a page listing each letter. How this detects Macroing is because if an account is Macroing, then the account will continue to press the moves excessively rather than answering the question.