“T + 3” refers to

the form, also known as a “trade ticket,” that is filled out when an order is entered into the market.

the form that is filled out and sent to the client confirming that the trade has been executed.

the fact that the settlement date will be three business days after the trade date, which is the “regular way settlement” for transactions involving stocks and corporate and municipal bonds.

a procedure to minimize the potential for money laundering.