2.3 Uncompressed OAB Version 2 and OAB Version 3 Browse File

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 The Browse file<2> contains one fixed size record per user, with members that point to offsets in the RDN Index file, the ANR Index file, and the Details files. The fixed size record contains data and offsets that account for all of the user's data in the OAB version 2 and OAB version 3 structure.

The records in the Browse file are sorted in alphabetical order according to the Address Book object display names and they allow for fast paging of Address Book object data. The Browse file has offsets into the other files for the display name, the surname, the office location, the X500 DN, the Simple Mail Transfer Protocol (SMTP) address, the e-mail alias, and the details record. The Browse file also maintains values for the object type and Address Book object display type. Each record is a fixed size. Fetching an entire record requires that the client follow each link from the Browse file and retrieve data from the other files. The header of the Browse file includes a file type, a record count, and a serial number. The serial number is a rotating hash of the RDN value of each record in the Browse file order.

OAB version 2 only includes support for encoding string data with characters in the ANSI character set code page of the Browse file. OAB version 3 added support for Unicode characters and additional properties to recipient record data. If the client supports Unicode, the Unicode files of OAB version 3 SHOULD be used.

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

 browse-file       =    OAB_HDR 1*16777213(B2_REC)