[macguillicuddy]

I'm just speculating as to what points are actually added but typically the flight plan includes 'airways' in addition to waypoints. Here's an example of a plan for London Gatwick (EGKK) to Edinburgh (EGPH):

``` EGKK/08R LAM1Z LAM L10 BPK UN601 INPIP INPI1E EGPH/24 ```

And to take a section out:

``` BPK UN601 INPIP ```

In this case, BPK and INPIP are two waypoints (one in the south of England and one in the north). UN601 is an airway that connects these two waypoints. The airway represents a ton of other waypoints between BPK and INPIP but that you don't need to specify manually in the flight plan. I suspect the additional waypoints added are the splitting of the airway into the underlying waypoints - but as I say it's speculation :-)