Protecting Project Resources
You can lock individual project resources from inside Designer by opening the Project Browser, and right clicking on any of the objects that you want to lock in. Select the Protect option to protect it. Once it's protected, it cannot be changed except by someone that has the permission to unprotect it, and modify it.

Protected resources are global or project resources that can only be edited by select users with the required roles. These roles are required to protect resources from being edited in the Designer, and do not apply to the clients. This means you can prevent a resource from being edited by other users who have Designer access. It is often used in scenarios where development work is finished on a window or object, and no further changes should be made to it. Other objects like Vision Templates or Alarm Pipelines are often protected so they may be used, but not modified.
Users without a required role will see the following message in the Designer when attempting to open a protected resource:

Users with a required role are allowed to modify the resource, but a message will appear informing them that the resource is protected, and will be asked how to proceed:

Additionally, a lock
icon will appear on the resource informing users that it is protected. An example can be seen on the 'Audit Events' window below:

To remove the protection, simply right click the object and select the Protect option to unprotect it.