Passing Annotations in CRM Organization Web Service

Hi All,

We have a requirement to pass an image file from BizTalk while creating an Entity in CRM, this image would be linked to that Entity. From doing some R&D I can see that attachments can be uploaded as Annotations using the Organization service but the problem is all the examples are showing the use of SDK and we are calling the Organization Web Service directly without using the SDK i.e. Key Value pairs in the XML, question is how do we pass Annotations in XML?

Thanks

Syed