Mike,
I have added all the main map references (with a few intermediates as well), and to simplify marking them all on the map, I followed these steps:
1. Created an Individual called
_MapMarkers //. (using the underscore to make it sort to top of Individuals list)
2. Created a Custom Fact called
MapMarker, consisting of
Name &
Location, (No date).
3. I then add a
MapMarker fact to
_MapMarkers // for every map reference.
NB If more are created, they will need to be added to
_MapMarkers // as well.
With
_MapMarkers // as focus, click on Map and mark all places for
_MapMarkers //. Then click on
Set Tasks, and change the Marker to one that stands out. Once this set opens, you can Tick/untick the
Check All box to turn them on/off
Now click the map again, but this time
Map all, this will create another marker set, with a different icon. You can now carry on as normal.
Note: This seemed the simplest solution, as one can't create a List/Set of Places to mark, and I couldn't see a simple way of filtering Places so that only those starting
OS-GB were marked. The above method also has the advantage that the markers can be turned on/off at will.
Thankfully, all the rigmarole above will only need to be done once
Those who don't want the bother, just import the attached Gedcom into your tree. It will all be done for you