Some more information from modfil11.txt:
// Another annotion about these tag fields: here you got some other fields.
// If you don't want to support them in your player, you should at least de-
// tect them. All these MODs have of course 31 instruments.
// 'FLT4', 'FLT8': Startrekker 4/8 channel file. ('FLT6' doesn't exists)
// 'CD81' : Falcon 8 channel MODs
// '2CHN' : FastTracker 2 Channel MODs
// 'yyCH' where yy can be 10, 12, .. 30, 32: FastTracker yy Channel MODs
// 'yyCH' where yy can be 11, 13, 15: TakeTracker 11, 13, 15 channel MODs
// 'TDZx' where x can be 1, 2 or 3: TakeTracker 1, 2, 3 channel MODs
// 'xCHN' where x can be 5, 7 or 9: TakeTracker 5, 7, 9 channel MODs
//
// Thanks must go to Inertia for most of these extra tag fields.
//
// All these formats, except for the FLT8 format, are *EXACTLY* the same as
// the standard M.K. 4 channel format; the only difference is the size of
// one pattern. The size of one pattern is calculated w/ the following
// "formula":
// (Nr_Of_Channels shl 8)
//
// ( Nr_Of_Channels shl 8 <====> Nr_Of_Channels*4*64
// ^ ^^
// | ||
// Note length: 4 bytes -----+ ||
// Lines/patttern: 64 ---------++
// )
// The tag '4CHN' doesn't exists.
//
// Some extra information about the "FLT8" -type MOD's:
//
// These MOD's have 8 channels, still the format isn't the same as the
// other 8 channel formats ("OCTA", "CD81", "8CHN"): instead of storing
// ONE 8-track pattern, it stores TWO 4-track patterns per logical pattern.
// i.e. The first 4 channels of the first logical pattern are stored in
// the first physical 4-channel pattern (size 1kb) whereas channel 5 until
// channel 8 of the first logical pattern are stored as the SECOND physical
// 4-channel pattern. Got it? ;-).
// If you convert all the 4 channel patterns to 8 channel patterns, do not
// forget to divide each pattern nr by 2 in the pattern sequence table!