The MAR is a database of building addresses and other location identifiers in the District. Each address in the database has been assigned a unique Address Identification Number (AID), map coordinates and other useful information. 

• Launch MAR Sample Client
• Download the MAR Batch Geocoder (.exe format)
  
• Master Address Repository Blog 
• Addressing Standards*
• Presentation*
• Address Anomalies*
• Data Dictionary* 
• Frequently Asked Questions*
• Local Update of Census Addresses (LUCA)*
• Calculating Confidence Levels in MAR Web Service*

The MAR:

• Facilitates analysis across systems and agencies. The MAR allows the District government to more easily compare information across databases and agencies. The format and quality of address information varies across government systems, making it difficult for government to identify all the activity associated with a given address. Now, DC Addressing Standards are built into the MAR. These standards define the valid components of DC addresses (AID, Number, Street Name, Street Type and Quadrant), including their correct formatting and spelling.
• Acts as a local gazetteer. It employs spellchecking and lists of street names and street types “aliases” (eg, MLK Ave) to make locating addresses as easy as possible. In addition to locating addresses, the MAR also helps users find intersections (4th Street NW and D Street NW), blocks (4th Street NW between D Street and E Street, or the 400 block of 4th Street NW), and place names (One Judiciary Square, also known as 441 4th Street, NW). In most cases, the MAR returns the specific building desired.
• Now informs users of alias names and condo units associated with the searched for address. This enhancement was added to simplify the process of finding associated alias names and condo information. There are future plans to add information about apartment units as well.
• Is built and distributed using DC’s service-oriented architecture. The MAR Sample Client is built from two SOAP web services: the MAR service and the BasicMap service. This makes it easy for DC agencies to embed standard address and spatial searching in their applications and Web Sites.

• Launch the MAR Sample Client