Depository Trust Company - DTC/Municipal Bond

http://www.investopedia.com/terms/d/dtc.asp

Definition of 'Depository Trust Company - DTC'
One of the world's largest securities depositories, it holds in excess of US$10 trillion worth of securities in custody. The DTC acts like a clearinghouse to settle trades in corporate and municipal securities. 
 Investopedia explains 'Depository Trust Company - DTC'
DTC is owned by many companies in the financial industry, with the NYSE being one of its largest shareholders. 

Definition of 'Municipal Bond'
A debt security issued by a state, municipality or county to finance its capital expenditures. Municipal bonds are exempt from federal taxes and from most state and local taxes, especially if you live in the state in which the bond is issued.

Also known as a "muni." 
 Investopedia explains 'Municipal Bond'
Municipal bonds may be used to fund expenditures such as the construction of highways, bridges or schools. "Munis" are bought for their favorable tax implications, and are popular with people in high income tax brackets.