Before editing a file linked to the AccuRev workspace it might make sense to lock this file on the mainframe first to let users know that this file is in work. It's usual in Endevor to lock a file before changing it. The corresponding Endevor action is Sign-Out.
The Sign-Out function is available on the context menu of a file selected either in an Endevor view or in the AccuRev workspace or in a COBOL or PL/I project.
If a developer doesn't sign-out the file, the synchronization process will sign-out the file in Endevor directly before the synchronization to Endevor is executed. If this sign-out fails because the file is signed-out to another user, then the synchronization request is rejected.
If a Sign-out on an Endevor file has been set, this information is not directly visible in AccuRev. It depends on the configured synchronization time interval. The next iteration will synchronize the changed Endevor file's attribute and then the Properties view will show the updated information.