additional information to use an existing private DNS on another subscription

Hi There,
In order to create MySQL Flexible server with an existing private DNS on another subscription, the "[reader](https://docs.microsoft.com/en-us/azure/role-based-access-control/built-in-roles#reader)" role is required on subscription level

if we can add this information, then it will be great and very helpful, as we were facing some difficulties and error msg is very general which is only mention "forbidden".
thank you.
Maadityo@microsoft.com

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#### Document Details

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* ID: ab572d66-e131-dcf9-8754-d8f8eea01cd5
* Version Independent ID: 75e64b41-cd3e-7bc1-a391-fad2b9a956da
* Content: [az mysql flexible-server](https://docs.microsoft.com/en-us/cli/azure/mysql/flexible-server?view=azure-cli-latest#az_mysql_flexible_server_create)
* Content Source: [latest/docs-ref-autogen/mysql/flexible-server.yml](https://github.com/MicrosoftDocs/azure-docs-cli/blob/master/latest/docs-ref-autogen/mysql/flexible-server.yml)
* Service: **mysql**
* GitHub Login: @rloutlaw
* Microsoft Alias: **routlaw**