About labels
Port, host, domain, and source labels enable you to group like items in sets. This makes configuring features that use these items easier. For example, you can group ports under a label and apply a single in-path or load-balancing rule to the set. The use of labels is optional. These guidelines apply to all labels:
• Labels are not case sensitive and can be any string consisting of letters, underscore, or hyphen. Spaces are not allowed. Label matching is not case-sensitive.
• To avoid confusion, do not use a number for a label.
• Labels that have in-path or other rules, such as QoS and peering rules, applied to them cannot be deleted.
• Use a comma-separated list when entering multiple ports, hosts, or domains. You can also use spaces and line breaks to separate domains.