Certain files in the operating system are required to have a specific format. The formats of the files that are provided with the operating system are discussed in the documentation for those files. If a file is generated by either the system or a user rather than provided on the distribution medium, it is discussed as a file format in this documentation. File formats often are also associated with header files that contain C-language definitions and structures for the files.
More information about the following file formats is provided in this documentation:
| Item | Description | 
|---|---|
| acct | Describes the format of the records in the system accounting files. | 
| ar | Describes the format of an archive file. | 
| audit | Describes values used by the auditing system as well as the structure of a bin. | 
| bootptab | Describes the default configuration database for the Internet Boot Protocol server (bootpd). | 
| CGM | Defines a file format for storage and retrieval of device-independent graphics. | 
| charmap | Defines character symbols as character encodings. | 
| core | Describes the structures created in a core file as a result of a core dump. | 
| cpio | Describes the cpio (copy in/out) archive file. | 
| eqnchar | Contains special character definitions for the eqn and neqn commands. | 
| lastlog | Defines the last login attributes for users. | 
| ldapattribmap | Defines AIX® to LDAP attribute name mapping to support configurable LDAP server schema. | 
| locale definition | Contains one or more categories that describe a locale. | 
| locale method | Specifies the methods to be overridden when constructing a locale. | 
| magic | Defines file types. | 
| mailrc | Sets defaults for the mail command. | 
| mh_alias | Defines aliases for the Message Handler (MH). | 
| mib_defs | Provides descriptions of Management Information Base (MIB) variables for the snmpinfo command. | 
| nroff and troff input | Specifies input file format for the nroff and troff commands. | 
| nterm | Describes the format of the terminal driver tables for the nroff command. | 
| profile | Describes the format of the profile and .profile files, which set the user environment at login time. | 
| queuedefs | Describes the format of the file used by the cron daemon to handle event types. | 
| sccsfile | Describes the format of a Source Code Control System (SCCS) file. | 
| setmaps | Defines the text of a code-set map file and a terminal map file. | 
| terminfo | Contains compiled terminfo source files. | 
| TIFF | Enables InfoCrafter to support scanned images that have been imported into Interleaf documents. | 
| trcfmt | Stores trace templates. | 
| troff | Describes the output language of the troff command. | 
| troff Font | Describes the format of the troff command font files. | 
| tunables | Centralizes tunable parameter values. | 
| UIL | Contains information on the user interface for a widget-based application. | 
| utmp, wtmp, failedlogin | Describes the format of the user and accounting information in the utmp, wtmp, and failedlogin files. | 
| vgrindefs | Contains the language definition database for the vgrind command. | 
| WML | Generates variable UIL compiler components. | 
| Item | Description | 
|---|---|
| ate.def | Determines default settings for use in asynchronous connections and file transfers. | 
| ATE Dialing Directory | Lists phone numbers that the ATE program uses to establish modem connections. | 
| Item | Description | 
|---|---|
| Devices | Contains information about devices on the local system that can establish a connection to a remote computer using the Basic Networking Utilities (BNU) program. | 
| Dialcodes | Contains the initial digits of telephone numbers used to establish remote connections over a phone line. | 
| Dialers | Lists modems used for Basic Networking Utilities (BNU) remote communications links. | 
| Maxuuscheds | Limits the number of instances of the uusched and uucico daemons that can run simultaneously. | 
| Maxuuxqts | Limits the number of instances of the BNU uuxqt daemon that can run simultaneously on the local system. | 
| Permissions | Specifies BNU permissions for remote systems that call or are called by the local system. | 
| Poll | Specifies when the BNU program should poll remote systems. | 
| Systems | Lists remote computers with which users of the local system can communicate using the Basic Networking Utilities (BNU) program. | 
| Item | Description | 
|---|---|
| 3270keys | Defines user keyboard mapping and colors for TELNET (3270). | 
| Domain Cache | Defines the root name server or servers for a DOMAIN name server host. | 
| Domain Data | Stores name resolution information for the named daemon. | 
| Domain Local Data | Defines the local loopback information for named on the name server host. | 
| Domain Reverse Data | Stores reverse name resolution information for the named daemon. | 
| /etc/ftpd.cnf | Specifies configuration parameters of the ftpd daemon to start a TLS session. | 
| .ftpcnf | Specifies configuration parameters of the ftp command to start a TLS session. | 
| ftpusers | Specifies local user names that cannot be used by remote FTP clients. | 
| gated.conf | Contains configuration information for the gated daemon. | 
| gateways | Specifies Internet routing information to the routed and gated daemons on a network. | 
| hosts | Defines the Internet Protocol (IP) name and address of the local host and specifies the names and addresses of remote hosts. | 
| hosts.equiv | Specifies remote systems that can execute commands on the local system. | 
| hosts.lpd | Specifies remote hosts that can print on the local host. | 
| inetd.conf | Defines how the inetd daemon handles Internet service requests. | 
| map3270 | Defines keyboard mapping and colors for the tn3270 command. | 
| netcd.conf | Defines parameters for the netcd daemon. | 
| .netrc | Specifies automatic login information for the ftp and rexec commands. | 
| networks | Contains the network name file. | 
| protocols | Defines the Internet protocols used on the local host. | 
| rc.net | Defines host configuration for the following areas: network interfaces, host name, default gateway, and any static routes. | 
| resolv.conf | Defines DOMAIN name server information for local resolver routines. | 
| rfc1108 | Contains the mapping between AIX® Trusted Network labels and rfc1108 labels. | 
| .rhosts | Specifies remote users that can use a local user account on a network. | 
| services | Defines the sockets and protocols used for Internet services. | 
| Standard Resource Record Format | Defines the format of lines in the DOMAIN data files. | 
| telnet.conf | Translates a client's terminal-type strings into terminfo file entries. | 
| cgaparams.sec | Defines the color graphics adapter (CGA) parameter keywords for the ndpd-host daemon and autoconf6 command. | 
| ndpdh.cnf | Defines the configuration file locations for the ndpd-host daemon and the autoconf6 command. | 
| sendh_anchor | Defines the trusted anchor for the ndpd-host daemon. | 
| sendr_anchor | Defines the trusted anchors for the ndpd-router daemon. | 
| tempaddr.conf | Defines if temporary addresses should be allowed or denied |