Use tags to label and categorize VPCs. This helps you create a business-centric view of your resources and simplifies resource search and aggregation.使用标签进行自动化运维
For guidance on designing tags, see Tag design examples.
Usage notes
Quota: Each VPC, vSwitch, and route table supports a maximum of 20 tags. This quota cannot be increased.
Security: Do not store sensitive information, such as passwords or AccessKey pairs, in tags. Tags appear in plaintext in billing reports.
Guidelines:
Each tag is a key-value pair. Tag keys and tag values are case-sensitive and cannot start with the prefixes
aliyun,acs:,http://, orhttps://.Each tag key must be unique per instance.
A tag must be attached to an instance.
Tags are specific to a region. For example, a tag created in the China (Hangzhou) region is not visible in the China (Shanghai) region.
You can edit the key and value of a tag, or remove a tag from an instance. Deleting an instance also deletes all of its tags. This action does not affect tags on other instances.
Add or remove tags
Console
To manage tags for a single instance, go to the VPC console. Find the instance, hover over the
icon in the Tags column, and then click Edit or Edit. To remove a key-value pair, click the 
icon next to it.If the Tags column is not visible, click the
icon in the upper-right corner of the VPC list to display it.To manage tags in batch: Select the VPCs you want to modify. In the lower-left corner of the page, choose Configure Tags>Batch Add Tags or Configure Tags>Batch Delete Tags.
To filter resources, click Filter by Tag at the top of the list. Then, select or enter a key-value pair to find matching VPCs.
API
Call the TagResources API operation to apply tags to specified resources in a single request.
Call the UnTagResources API operation to remove tags from specified resources in a single request.