Hi,
with the help of genious TypViewer V4.5.7 I succeeded integrating original GarminExtraPois into CN 2015.20 NT typ file.
And it works! See post [Only registered and activated users can see links. ].
(Load custom typ, select all text, copy, load original TYP, display all text, remove it all and paste)

The same procedure doesn't work on pid 3199 i0000c7f.typ Topo Switzerland V4 Winter.
Save the file quits with "An error appears when creating file. Error number 9. Description: Subscript out of range".

As there are only 14 ExtraPois in the original file, I tried definingt them in my custom typ file.
Save is ok, ExtraPois are in the typ file, but are not rendered by Basecamp?

It seems as if the 'link' is missing, or in french: les definitions sont la, mais ça croche plus...

Thankful for any advice...