Applies a Tag to a user. If the tag text does not already exist, it is created. The newly created ID is accessible via the returned TagData. 

This method can be accessed through the Tags.asmx file located in:

~/Workarea/webservices/WebServiceAPI/Community/Tags.asmx

[SoapHeader("AuthHeader")]
[SoapHeader("RequestInfoHeader")]
[WebMethod(MessageName = "AddTagToUser with tag id", Description = "Applies a Tag to a user.  If the tag text does not already exist, it is created.  The newly created Id is accessible via the returned TagData.")]
public void AddTagToUser(long tagId, long userId);

<SoapHeader("AuthHeader")>
<SoapHeader("RequestInfoHeader")>
<WebMethod(MessageName = "AddTagToUser with tag id", Description = "Applies a Tag to a user.  If the tag text does not already exist, it is created.  The newly created Id is accessible via the returned TagData.")>
Public Function AddTagToUser(tagId As long, userId As long) As void