Resource Orchestration Service (ROS) provides a tag management feature to categorize its stacks and templates.
Each tag consists of a key-value pair. ROS tags have the following limits:
Standalone tags are not supported. A tag must be attached to a stack or template.
A stack or template can have a maximum of 20 tags.
Tag keys must be unique for each stack.
For a template, tag keys must be unique. A new tag overwrites an existing tag that has the same key.
Tags are specific to each region. For example, tags created in the China (Hangzhou) region are not visible in the China (Shanghai) region.