It may be that you want to overlay multiple numbers at the same time. This can obviously be achieved by calling numberOverlay several times, but the latency involved in making multiple round trips will slow down your system's response time. To solve this problem, the numberOverlayMultiple function was created
The parameters required are exactly the same as for the previous example, but this time we will provide several of them. Depending on the interface you are using the method of delimitting entries will be slightly different, please check the examples for details.
Note, please be especially careful when using this API call with GET or POST requests over the REST interface. The positioning of square brackets is very important and, due to limitations of the protocol, not necessarily what would be expected.
Suppose we want to overlay one destination with two different numbers and a second destination with a third overlaying number. We will use the "numberOverlayMultiple" method and we will need to send a total of 12 pieces of information to the server.