A common difficulty in Domino is to calculate the correct URL of an embedded image in a RichText field.
When a WebService which should return the correct URL of any image, may it be embedded or attached as file, is called from a remote server, the WebService should look at the HTML source of the web page where the picture is embedded, and then parse the contents to find the picture file URL (search for "img" and then the next "src" tag) and send the URL of the picture from the parsed content to the remote server.