@Mahi this is a really old pattern (at least 7,5 years old if you look at the oldest comment) and back then the rules have been different. Nowadays at least four keywords are needed so it's easier to search for pattern. It also can help more people to find your pattern.
Whenever I make a pattern it says that we need at least 4 keywords. And in this pattern there are 3. It doesn't get accepted if i have less than 4 keywords. So how did this pattern get accepted?