As per your requests, we've added a new feature that can be enabled for you according to your preferences: The option to have a PNR locked automatically once it's ticketed.
Once the ticketing process is complete, the PNR will be locked for changes. It can then only be unlocked by an administrator with a PNR master key.
Thus is true for PNRs created from both the CRS and the website, either by agents or direct clients.
Should you decide you wish to have this feature enabled for your company, please contact our support team.