Explanation

Box 1: " Microsoft.Resources/subscriptions/resourceGroups"
Box 2: "Deny",
Sample - Enforce tag and its value on resource groups
},
"policyRule": {
"if": {
"allOf": [
{
"field": "type",
"equals": "Microsoft.Resources/subscriptions/resourceGroups"
},
{
"not": {
"field": "[concat('tags[',parameters('tagName'), ']')]",
"equals": "[parameters('tagValue')]"
}
}
]
},
"then": {
"effect": "deny"
}
}
}
}
References:
https://docs.microsoft.com/en-us/azure/governance/policy/samples/enforce-tag-on-resource-groups