This topic provides an overview of domain name tags. Each tag is represented by a string of characters. In Alibaba Cloud CDN, you cannot define tags, but you can attach tags to domain names, detach tags from domain names, and use tags to group or filter domain names.


  • Each tag is a key-value pair (Key:Value), which consists of a key and a value.
  • Up to 20 tags can be attached to a domain name.
  • For the same domain name, the key for each tag must be unique. If two tags have the same key but different values, the current tag overwrites the previous tag. For example, if you configure the Key1:Value1 tag and then the Key1:Value2 tag for the domain name, only the Key1:Value2 tag is attached to the domain name.
  • A key cannot start with aliyun or acs, contain http:// or https://, or be left unspecified.
  • A value cannot contain http:// or https://, but can be left unspecified.
  • A key can contain up to 64 Unicode characters.
  • A value can contain up to 128 Unicode characters.
  • Tags are case-sensitive.


You can use tags to perform the following operations:

  • Attach tags to domain names to identify or group the domain names. For more information, see Attach tags.
  • Detach tags from domain names. For more information, see Detach tags.
  • Manage domain names based on their tags. For more information, see Manage domain names by tag.
  • Query the domain names to which specific tags are attached. For more information, see Filter domain names by tag.