pattern-fields.json

{
    "properties": {
        "displayName": "Allowed locations",
        "policyType": "BuiltIn",
        "description": "This policy enables you to restrict the locations your organization can specify when deploying resources. Use to enforce your geo-compliance requirements. Excludes resource groups, Microsoft.AzureActiveDirectory/b2cDirectories, and resources that use the 'global' region.",
        "mode": "Indexed",
        "parameters": {
            "listOfAllowedLocations": {
                "type": "Array",
                "metadata": {
                    "description": "The list of locations that can be specified when deploying resources.",
                    "strongType": "location",
                    "displayName": "Allowed locations"
                }
            }
        },
        "policyRule": {
            "if": {
                "allOf": [{
                        "field": "location",
                        "notIn": "[parameters('listOfAllowedLocations')]"
                    },
                    {
                        "field": "location",
                        "notEquals": "global"
                    },
                    {
                        "field": "type",
                        "notEquals": "Microsoft.AzureActiveDirectory/b2cDirectories"
                    }
                ]
            },
            "then": {
                "effect": "Deny"
            }
        }
    }
}