Sorry, looks like you might be right after reading some NAT bulletins etc. The link I posted seems to be based on a data provider who has changed from the ARINC 424 format but not mentioning that at all. It looks like the default ARINC 424 is actually N5530 for half degree coordinates, but because of so many pilot errors they are strongly dis-encouraging everyone from using this format and instead change to something else, e.g H5530, which at least Navigraph's source has done already. Aerosoft I cannot speak for, as I don't use NavDataPro myself
(NAT OPS Bulletin 2008_003)
Checking e.g AIP Iceland ENR 184.108.40.206, you'll see:
Due to the unresolved potential for FMC insertion errors:
Aircraft navigation data shall NOT contain waypoints in the Reykjavik Control Area in the ARINC424 paragraph 7.2.5 format of "Nxxxx".
If an aircraft operator or flight planning service has an operational need to populate data bases with half-degree waypoints in the Reykjavik Control Area, they are advised to use the alternate format "Hxxxx".
So it looks like the default is actually N#### after all, but that some data providers have already changed this to e.g H####
Hopefully I got it right this time @Frank Docter