How do I read this flight plan route?

Question

When I create a flight plan using SimBrief, for example for London Gatwick (EGKK) to Dublin Airport (EIDW), it generates the following route:

NOVM1M NOVMA L620 NIBDA N14 MEDOG L18 ABLIN ABLI1L

So far I know that NOWM1M is the departure (SID) and ABLI1L is the arrival (STAR). In this case, NOVMA is the last waypoint of the departure and ABLIN is the first waypoint of the arrival. In a TBM9 aircraft for example, I can enter those routes into the FMS (G3000) by selecting it as the arrival and departure of the respective airports.

My question is about the waypoints in between: L620 NIBDA N14 MEDOG L18. As far as I understand, a waypoint's name should consist of exactly five alphanumerical characters. Those would then only be NIBDA and MEDOG. In Microsoft Flight Simulator 2020, I can find and add those waypoints as enroute waypoints. I can however not find L620, N14 or L18.

Also in the chart created by SimBrief, there are more waypoints plotted than appear in the list, such as KENET.

My questions are:

1. What are L620, N14 and L18, and why can I not find them in the FMS?
2. Why are there additional waypoints showing on the map that do not appear on the list?

Thank you for any clarification you can give.

Answer 1

Those are airways connecting the waypoints of your route. The map you show already includes all waypoints along the route (like e.g. KENET on airway N14). When filing such a route, you are expected to follow all these waypoints and not go direct between the waypoints in the route summary (e.g. NIBDA direct to MEDOG would look very different compared to airway N14).

One can enter all waypoints one by one without including the airway information. The full document from Simbrief will contain a long table with all waypoints. However, that is quite tedious and most modern flight management systems (FMS) will allow entering a route with airways. On the G3000, it works likes this:

Adding an individual airway to a flight plan:

1. For the active flight plan: From MFD Home, touch Flight Plan. [...]
2. Scroll the list if necessary and touch a waypoint options button to display the 'Waypoint Options' Window.
3. Touch the Load Airway Button to display the 'Airway Selection' Screen.
4. Touch the Sort A→Z Button to select/deselect alphabetical sorting of the airway waypoints.
5. Scroll the list if necessary and touch an airway selection button to select the airway and display the 'Select Exit' Window (if Sort A→Z is selected, the exit points are displayed in alphabetical order, not the order they appear in the airway).
6. Scroll the list if necessary and touch an airway exit point selection button to select the airway exit point. The airway waypoint sequence is now show on the 'Airway Selection' Screen.
7. Touch the Load Airway Button to insert the airway into the active or standby flight plan.

^{(Garmin G3000 - Cockpit Reference Guide - TBM 930)}

I do not know if the G3000 in MSFS2020 works this way, but support for the simulator is off-topic here.