Question: Let us suppose that I question the behaviour or ruling of a moderator. This may be something serious or a minor quibble that I think is worth addressing.

I need to give examples in order to justify my concern. However I hesitate to name a person in a question here on Meta.

Is there a way to do this discreetly? What is it?

Answer: 
> 
> This may be something serious or a minor quibble that I think is worth addressing.
> 
> 
> 

For a minor issue, bringing it up here on Meta is fine; questions asking about certain *actions* are perfectly fine, provided that you don't make the question about the *person*. Make sure the question stays focused on the action and not the person who made the action.

You can also raise a custom moderator flag. Mods are generally discouraged from handling flags about themselves (or on their posts), because it's a conflict of interest; one of the other site moderators will review your flag.

For something more serious, you can use the [Contact Us](https://interpersonal.meta.stackexchange.com/contact) form to reach out to the Stack Exchange staff (who run the site). This will initiate the [Moderator Conduct Review Process](https://meta.stackexchange.com/a/336178/294691).
Contacting SE Staff would work through the [Contact Us](https://interpersonal.meta.stackexchange.com/contact) form. It is discreet since moderators can't see these reports.

Alternatively flagging one of your posts as a custom flag and explaining in short what happened (with the mention of the moderarator) works too but since the mod can see this flag (althought they are encouraged to pass on to another mod for review) it is not discreet as requested.