Why every MLB player is wearing No. 42 today
Phillies unveil Players Weekend uniforms, along with individual nicknames
MLB players will be allowed to wear nickname jerseys during newly created Players Weekend later this month - ESPN
Baseball Loosens Rules and Opens Door to a Vibrant Weekend - The New York Times
Memo: MLB players can use nicknames on back of jersey, wear bright-colored shoes during 'Players Weekend
MLB Unveils Alternate Nickname Jerseys For Player's Weekend
Players' Weekend, Nicknames on Jerseys Return to MLB on August 23–25, by Chicago White Sox
Who is the only MLB player to have his first name on his jersey? - Quora
Ranking MLB's City Connect uniforms - ESPN
Baseball - Wikipedia