Is it possible to do code snippets with variables?

RS code .snippet xml files indicates the possibility to use variables in your snippets.
For example the "Array of num, 2x4 has its name as a litteral.

name myNumArray2x4 The name of the array

However. Without the possibility to make this an actual variable what is the point of it?
According to Microsoft you should be able to to insert TM_SELECTED_TEXT, or ever better CLIPBOARD into the snippet. A prompt would be even more fantastic.

Is this possible? If so what syntax would RS approve?