A personal piece of punctuation (5)
I believe the answer is:
colon
This clue might be a double definition.
'a personal piece' is the first definition.
'colon' can be an answer for 'piece' (colon is a kind of piece). I'm not sure about the 'a personal' bit.
'punctuation' is the second definition.
(colon is a kind of punctuation)
'of' is the link.
Can you help me to learn more?
(Other definitions for colon that I've seen before include "City at the Caribbean entrance to the Panama Canal" , "Stop (on the inside!)" , "Costa Rican currency" , "Panama port; part of intestine" , "Start of one canal" .)