2.5 Uncompressed OAB Version 2 and OAB Version 3 ANR Index File

 The ANR Index file<5> enables ANR. The server sorts values for the display name, surname, office location, and e-mail alias together into one structure so that a single search can find Address Book objects based on multiple properties.

The ANR Index file is structured similarly to the RDN Index file, but does not contain a PDN table. Each record is a variable size and has four offsets that construct a threaded tree structure. Records have an index of master records in the Browse file and the value portion is either an office location string, a surname string, an alias string, or a display name string. The root of the ANR index tree is the first node in the file; therefore no root offset is required in the header.

The following ABNF definition shows the format of an uncompressed OAB version 2 or OAB version 3 ANR Index file.

 anr-file       =    OAB_HDR 1*ANR_REC