# Tag
<a name="API_Tag"></a>

A custom key-value pair that's associated with a resource.

## Contents
<a name="API_Tag_Contents"></a>

 ** Key **   <a name="cloudmap-Type-Tag-Key"></a>
The key identifier, or name, of the tag.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 128.  
Required: Yes

 ** Value **   <a name="cloudmap-Type-Tag-Value"></a>
The string value that's associated with the key of the tag. You can set the value of a tag to an empty string, but you can't set the value of a tag to null.  
Type: String  
Length Constraints: Minimum length of 0. Maximum length of 256.  
Required: Yes

## See Also
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For more information about using this API in one of the language-specific AWS SDKs, see the following:
+  [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/servicediscovery-2017-03-14/Tag) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/servicediscovery-2017-03-14/Tag) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/servicediscovery-2017-03-14/Tag)