Enabling ASR for your environment helps you get quick assistance when you have a hardware issue - Ops Center takes asset information when a hardware incident occurs, and generates a service request based on contact information and MOS credentials that you've provided.
The trick, though, is that you enable ASR for your entire environment. You can provide separate contact info for some groups, but when you enable it it's on for all assets that are associated with the credentials. So, what if you're performing some hardware maintenance, and you don't want to accidentally cause ASR to open a service request?
In cases like this, you can add an asset to a blacklist, to prevent ASRs from being generated for it. Select the Enterprise Controller from the admin section of the UI, then click configuration. In the list of subsystems, select Auto Service Request. You can then enter one or more serial numbers in a comma-separated list in the serial blacklist field to disable ASR creation for those assets. Monitoring of the assets still happens, and ASRs are created for other assets as normal.