If I'm not mistaken _2Z, _4Z, _8Z means the # of note zone limits.

They might also be velocity zones.

The two letter prefixes describe the musical section + the phrase complexity

MA for example, M is a Main section, A is the level of complexity
MB M is Main section, B is more complex than A
MC M is Main, C is more complex than B

Complexity suggests... Verse, chorus, solo sections, as an example. The verse being basic, the chorus has the drummer increasing the complexity...

So the second character is always a grade of complexity: A, B, C, D

The first letter is always a descrption.
M = Main section
F = Fill-in
I = Intro
E = Ending
B = Break

That said, you can use any phrase for any thing you desire, just because it is listed a FB (Fill-in with some complexity) does not mean you can’t use it for a Main section... you are free to use whatever you want for whatever purpose.

If you put the drum MA, with a bass MA, with a guitar MA, with a bass MA of the same name together, they will create a coherent pattern... that sound like they belong together. They are not pre assembled (on purpose) as you would find in an Arranger Keyboard, rather they are offered as individual phrases so you can combine and recombine them to make *your own*...

The Arpeggio suffix designation “N” and “C” are found in the MONTAGE, not the Motif XF... in the Motif XF these were referred to as “ES Type” and “XS Type”.

N _ no chord is necessary for the Arp phrase to play the riff. This type of phrase introduced back in 2003 (Motif ES) where a musical riff could be triggered by using just the root. Triggering that note in different regions of the keyboard will transpose the phrase accordingly.

C _ chord quality is necessary to define the Arp phrase. This type of phrase was introduced in 2007 (Motif XS) where a musical riff could be made to follow the chord but the phrase is fixed to play in a particular region... allowing you to trigger/control the chord intelligence from any region yet have the phrase sound in the proper range for the instrument.

Example: using an electric piano sound “Natural Wr”... try the following two versions of an Arpeggio phrase. This is a simple keyboard riff type phrase made up of triads (3-note chords)... They are the same phrase, treated differently:

Assign the following phrase (MONTAGE)
Category: Keyboard
Sub: Pop Rock
Number: 577
Name: MA_6/8 Pop _N

To trigger the arpeggio’s stored riff you only need to enter a single note indicating the key in which you want the riff to sound. Play the “F” above middle “C”… and listen.
Now play an “F” anywhere else on the keyboard – notice the phrase adjusts to sound in that region.

Now Assign the following phrase that requires a Chord (MONTAGE)
Category: Keyboard
Sub: Pop Rock
Number: 570
Name: MA_6/8 Pop _C

To trigger the Arpeggio’s stored phrase you must define a chord quality/tense. If you only trigger the “F” above middle “C” you will immediately understand the difference. At minimum two notes to define major or minor. F-A to define F Major. F-Ab to define F Minor. Major/minor triads in all inversions work. As you move the trigger chord to different octaves the phrase remains fixed to sound in the original region.

Basically, if you understand Type ES - that is now referenced by the suffix “N”
Type XS is referenced by the suffix “C”