This page is for the FS which can be mounted for NCAs with MountContent*. FS-type below is the in32 for "MountContent". MountContent throws errors when trying to access a NCA-type with a FS-type not listed below.
NCA-type0
FS-type5
Only contains the .cnmt file.
NCA-type1
FS-type2
NCA-type2
Unknown. Presumably what the nandsys 8XX titles use.