# AWS::SNS::Topic Tag

## Syntax

To declare this entity in your AWS CloudFormation template, use the following syntax:

### JSON

<pre>
{
    "<a href="#key" title="Key">Key</a>" : <i>String</i>,
    "<a href="#value" title="Value">Value</a>" : <i>String</i>
}
</pre>

### YAML

<pre>
<a href="#key" title="Key">Key</a>: <i>String</i>
<a href="#value" title="Value">Value</a>: <i>String</i>
</pre>

## Properties

#### Key

The key name of the tag. You can specify a value that is 1 to 128 Unicode characters in length and cannot be prefixed with aws:. You can use any of the following characters: the set of Unicode letters, digits, whitespace, `_`, `.`, `/`, `=`, `+`, and `-`.

_Required_: Yes

_Type_: String

_Update requires_: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

#### Value

The value for the tag. You can specify a value that is 0 to 256 characters in length.

_Required_: Yes

_Type_: String

_Update requires_: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)