AppIndicator.Indicator:ordering-index

"ordering-index"             Number                : Read / Write

The ordering index is an odd parameter, and if you think you don't need it you're probably right. In general, the application indicator try to place the applications in a recreatable place taking into account which category they're in to try and group them. But, there are some cases where you'd want to ensure indicators are next to each other. To do that you can override the generated ordering index and replace it with a new one. Again, you probably don't want to be doing this, but in case you do, this is the way.