*tags(server=~backend\*)* | Returns only tags that occur in series matching the filter expression.
*tag_values(server)* | Return tag values for the specified tag.
*tag_values(server, server=~backend*)* | Returns filtered tag values that occur for the specified tag in series matching those expressions.
*tag_values(server, server=~backend*, app=${apps:regex})* | Multiple filter expressions and expressions can contain other variables.
*tag_values(server, server=~backend*, app=~${apps:regex})* | Multiple filter expressions and expressions can contain other variables.
For more details, see the [Graphite docs on the autocomplete api for tags](http://graphite.readthedocs.io/en/latest/tags.html#auto-complete-support).
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@@ -124,7 +124,15 @@ Example:
### Variable Usage in Tag Queries
Multi-value variables in tag queries use the advanced formatting syntax introduced in Grafana 5.0 for variables: `{var:regex}`. Non-tag queries will use the default glob formatting for multi-value variables. Checkout the [Advanced Formatting Options section in the Variables]({{<relref"reference/templating.md#advanced-formatting-options">}}) documentation for examples and details.
Multi-value variables in tag queries use the advanced formatting syntax introduced in Grafana 5.0 for variables: `{var:regex}`. Non-tag queries will use the default glob formatting for multi-value variables.
Example of a tag expression with regex formatting and using the Equal Tilde operator, `=~`:
```text
server=~${servers:regex}
```
Checkout the [Advanced Formatting Options section in the Variables]({{<relref"reference/templating.md#advanced-formatting-options">}}) documentation for examples and details.
