Character Set Specifications

The key cannot be left blank or be an empty string.

• In Deutsche Telekom, a tag key can contain uppercase letters, lowercase letters, digits, hyphens (-), underscores (_), and sign @.
• In other environments, a tag key cannot contain the following characters: ASCII (0-31), equal signs (=), asterisks (*), left angle brackets (<), right angle brackets (>), backslashes (\), commas (,), vertical bars (|), and slashes (/).

The value cannot be left blank but can be an empty string.

• In Deutsche Telekom, a tag value can contain uppercase letters, lowercase letters, digits, hyphens (-), and underscores (_).
• In other environments, a tag value cannot contain the following characters: ASCII (0-31), equal signs (=), asterisks (*), left angle brackets (<), right angle brackets (>), backslashes (\), commas (,), vertical bars (|), and slashes (/).