Attached are three examples of the different ways in which to use the API in order to use Inserts with SMS.
The first way would be to use a CSV file with all the proper headings and the contents of the SMS inserts along with destination telephone #'s. I've found this to be the easiest way and the CSV file can contain many destinations.
The next way would be to build the inserts directly into the XML. Attached I have two examples of how to accomplish this. The example labled sms_inserts_nocsv.xml is in my opinion the cleanest of the two examples on embedding the inserts directly into the XML.
The other example shows duplicating what would normally appear in the CSV file directly into the XML but using this method, if the spacing is not exact you will get an error.
Using this same technique you could also do this for email.