A tag key, such as Stage or Name. A tag key cannot be empty. The key can be a maximum of 128 characters, and can contain only Unicode letters, numbers, or separators, or the following special characters: + - = . _ : /
An optional tag value, such as Production or test-only. The value can be a maximum of 255 characters, and contain only Unicode letters, numbers, or separators, or the following special characters: + - = . _ : /