# Image Tag Data Formats

#### Description

You can attach a custom tag to a private image to facilitate private image management.

#### Data Formats

Data format of tag

- The data format is key.value. If a key is added, a tag is added. In other cases, the tag is modified.
- The tag key can contain a maximum of 36 characters, and the tag value can contain a maximum of 43 characters. The tag value can be an empty character string.
- The tag can contain only digits, letters, underscores (_), and hyphens (-).

Data format of image_tags

- The data format is {"key": "keyA", "value": "valueA"}. If the added key A exists, the tag is updated.
- The tag key can contain a maximum of 36 characters, and the tag value can contain a maximum of 43 characters. The tag value can be an empty character string.
- If the first and last characters of the tag key and value are spaces, the system deletes the space by default.

#### Data Formats (Native OpenStack)

Data format of tag

- The data format is key. If a key is added, a tag is added. In other cases, the tag is modified.
- The tag key can contain a maximum of 255 characters.
- The tag can contain only digits, letters, underscores (_), and hyphens (-).

Parent topic: Common Parameters