What do all these letters B,D,E,F,H,K,L,M,N,P,R have in common that none of the other in the english alphabet has?

Question

What do all these letters B,D,E,F,H,K,L,M,N,P,R  have in common that none of the other in the english alphabet has?

bobpursley · Answer

all require the pencil to be lifted at least once before the letter is finished.

Ms. Sue · Answer

But A, Q, X, and Y also require the pencil to be lifted.

David Q · Answer

And L doesn't require the pencil to be lifted.

Reiny · Answer

I don't even have a pencil. How do I decide?