Applying tagging
Every subscription, resource group, and resource within Azure can have metadata assigned in the form of tags. Tags are essentially a set of key/value string pairs that can be applied either via the portal, PowerShell, or Azure Resource Manager (ARM) templates.
There are a few limitations to be aware of. Most resources can use tags, but there are exceptions. See https://docs.microsoft.com/en-us/azure/azure-resource-manager/management/tag-support for details of services that don't.
Tags can only be applied to resource model components, not classic models:
- Tag names are limited to 512 characters, except for storage accounts, which are limited to 256.
- Tag values are limited to 256 characters, except for storage accounts, which are limited to 128.
- A maximum of 50 tags can be used on a resource.
- Tags on a component do not automatically inherit tags from a resource group (but this can be set using a policy).
- Tags cannot contain the following symbols...