Indicate whether the alias is used in any rule or not

[dca00]

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Is your feature request related to a problem? Please describe.

It would have added great value to the admin UI, from a sysadmin's perspective, if there was an indicator of whether the alias is or is not used in any rule, in the highlighted empty space.

Describe the solution you like

Describe alternatives you considered

Manually checking every rule

Additional context

N/A