An excellent example of the ambiguity that exists between regulatory and technical requirements. ICAO require positions in Lat/Long to be referenced to the WGS 84 geodetic datum in the format DDMMSS/DDDMMSS.
The technical requirement for formatting in RNAV/FME receivers usually uses the format DDMM.MM/DDDMM.MM
You guys be careful now
BTW - the largest difference between WGS84 and local datum co-ordinates is, I believe, in Japan, and it's around 1.8km