Constraints and Limitations¶
The following are basic constraints on using tags:
Item | Specifications |
|---|---|
Maximum number of key-value pairs you can add for each resource | 20 |
Tags of each resource | For each resource, each tag key must be unique, and each tag key can have only one tag value. |
The maximum predefined tags that each account can create. | 500 |
Predefined tags | Predefined tags cannot be identical. Either their keys or values must be different. If you create a predefined tag that is identical to an existing predefined tag, the existing predefined tag will be overwritten. |
Tag keys | A tag key can contain a maximum of 36 characters, including only digits, letters, hyphens (-), at signs (@), and underscores (_). |
Tag values | A tag value can contain a maximum of 43 characters, including only digits, letters, hyphens (-), at signs (@), and underscores (_). |
Note
Not all resources are supported by TMS. For which services and resources are supported, see TMS and Other Services.