Update Sign-a-Package.md

Author: karann-msft

docs/create-packages/Sign-a-Package.md

@@ -12,6 +12,9 @@ ms.reviewer: anangaur
 
 Signed packages allows for content integrity verification checks which provides protection against content tampering. The package signature also serves as the single source of truth about the actual origin of the package and bolsters package authenticity for the consumer. This guide assumes you have already [created a package](creating-a-package.md).
 
+> [!Important]
+> Package signing is currently supported only when using nuget.exe on Windows. Verification of signed packages is currently supported only when using nuget.exe or Visual Studio on Windows.
+
 ## Get a code signing certificate
 
 Valid certificates may be obtained from a public certificate authority like such as [Symantec](https://trustcenter.websecurity.symantec.com/process/trust/productOptions?productType=SoftwareValidationClass3), [DigiCert](https://www.digicert.com/code-signing/), [Go Daddy](https://www.godaddy.com/web-security/code-signing-certificate), [Global Sign](https://www.globalsign.com/en/code-signing-certificate/), [Comodo](https://www.comodo.com/e-commerce/code-signing/code-signing-certificate.php), [Certum](https://www.certum.eu/certum/cert,offer_en_open_source_cs.xml), etc. The complete list of certification authorities trusted by Windows can be obtained from [http://aka.ms/trustcertpartners](http://aka.ms/trustcertpartners).