Specifying a system release
For any OT system you can specify release versions. In order to do that, go to INVENTORY/SYSTEMS and select the OT system. Then, in the release table at the bottom of the browser window, click on "Add". You can now specify a release (version) identifier and an optional target date. The username will be added automatically.
The release version is simply a label. It can be a number, but it could also be text. It's whatever makes sense for you to identify a specific release.
Signing a release
If all your system components are conformant with the release, you can express this fact by clicking on "Sign release". All components will then be set to the release that you have selected.
You can also release individual or multiple devices in the INVENTORY/DEVICES section. In order to do that, select the devices you want to sign (usually after filtering the inventory listing in a way that allows you to easier find the devices you are looking for), and then click on "Set Release".
In the dialog box that pops up, enter the appropriate release label and an optional comment.
Setting a release as part of the edit process
Any time you make manual changes to a device configuration, you have the opportunity to set a release label. The release dialog pops up as soon as you click on the Save button in the edit dialog.
Checking configuration drift
If system components "drift" away from their released configuration, this challenges system configuration integrity. While configuration changes for an individual device, such as installing a new software version, may be perfectly ok for that device when viewed in isolation, the risk exists that other system components with whom that device interacts don't respond well to the configuration change. Release management can help a good deal in protecting system integrity.
In order to check for configuration drift, open the system profile for the system in question. Then, in the port list section and in the endpoints section, check the release labels for each device. If the release label is highlighted in orange, this indicates that the device's configuration was changed after release.