If you are new fan (or relatively new), these might be some questions you may have:

What does the term KTBFFH stand for?

It means “Keep the blue flag flying high”. There is a related song/chant.

What does the term COYB stand for?

It stands for “Come on you Blues”

Which club do we hate the most?

Traditionally, we really hate Leeds and everybody hates Milwall, duh.

But in the modern times, there has been a fierce rivalry with Manchester United, Arsenal and Tottenham.
During Mourinho’s first stint, Liverpool undeniably had the 1st spot.

What song is played at Stamford Bridge before kick-off?

You are probably looking for “Blue is the color” or “Liquidator”.