What does a small shaved or tinted patch of hair on the head mean?

I keep seeing people who are clean shaven, with nice haircuts and in decent attire, with a small patch of hair (an area of about 1 inch) shaved off of the back of their heads or on the crown, or on one side of the head, etc. It is a very distinct, noticeable, purposely inflicted shaved spot! The rest of their hair is normal. What does that mean? Is it some sort of secret message? Just as strange; if they don’t have a small patch of hair shaved off; they have a patch of hair dyed a noticeable different color; the rest of their hair is natural. Is it just a new trend?