GM/WM/CSF masks and coordinate spaces

Dear conn-team,

after preprocessing and denoising, I find a number of new .nii-files in my subject's folder. Regarding this, I have these questions:

1) I assume the following (my question is: are the following assumptions correct?):

wc1ct1.nii: GM mask in subject space
wc2ct1.nii: WM mask in subject space
wc3ct1.nii: CSF mask in subject space

When I open these files in flsview, it displays "Coordinate Space: Aligned Anatomical". I don't know what this is supposed to mean, but I think it's probably just meant to be subject space (is that correct?).

2) What are the other files (wc0ct1.nii,c1ct1.nii,c2ct1.nii,...,ewc1ct1.nii,.....)? They also seem to be some kinds of masks in "aligned anatomical" coordinate space, but it is not quite clear to me what exactly they are.

3) How do I obtain a GM mask in MNI space?

Thank you!

Kind regards,
Sascha