I've had a bee in my bonnet about the need for national flags on all and any scenery mod, because without the national flag, it is often difficult to identify just where a particular mod is located in the world.
My reasoning is that without the flag, it will be near on impossible for anyone to carry out a search for a particular region's mods, and as such, mods not so tagged will soon disappear from the collective experience. That is a real pity.
I have a couple of suggestions, actually.
First, for local mods (all within one country) make it compulsory to include the country's flag, and for Global, or trans-national mods, allow the use of the UN flag to identify it as such.
Second - airlines by their very nature are associated with a home country, as are helicopters, light planes, etc, so I'd suggest that the country flag become a compulsory addition to livery packs, as well. (Same runes - UN flag if a pack covers liveries from several countries)
Adopting the second suggestion would allow us to search for liveries that are suitable for our areas of interest, rather than searching through the many liveries out there, just as it does for scenery mods.