If auditing is on for a particular file (see the FileAlter command, operand Audit), when the file is saved, audit information describing the updates is written to disk as well. The audit trail describing these updates, as well as updates from prior sessions, can be viewed during subsequent Edit or List sessions (see the SessionAlter command, operand DISP).
The audit trail can also be used as a means of restoring a file to a previous status (see the FileAuditRollback command).
Auditing is supported for BIM and workstation files. It is not supported for PDS or VSE files.
Other related commands include:
Format of the Audit Trail
The audit trail is composed of two types of lines:
Text lines are copies of lines from the file. For example, if a line is deleted from a file, a copy of the line is written to the audit trail.
Control lines describe the update events. Control lines are often associated with text lines. For example, in the above example of deleting a line, three lines would be written to the audit trail, a .DEL control line, followed by the deleted text line, followed by a second .DEL control line.