Forgive me if this has already been brought up, but until recently I only ever manually installed mods (since Morrowind), and have come to love NMM for its versatility and application (my favourite feature so far is the fact that I can layer and overwrite mods, but uninstall them again while replacing the prior mods files). Though I have noticed it'd be nice to have one feature, and that is the option to right click on mods and add user notes. Forgive me if this has already been suggested, or even implemented (and I'm too scatterbrained to find it), but I think it'd be useful; especially to those who extensively mod their games.
What I mean is, for example, say I install a full retexture to Skyrim, and then layer another mod that retextures just the trees, and yet another mod that retextures the leaves on those trees. It'd be nice to be able to right click the full retexture mod in NMM and make a note saying something along the lines of "base retexture mod", and then right click the tree mod to give it a note saying "installed after full retexture", and then finally make a note on the leaf retexture saying "installed after full, and tree retexture".
Or for another example, say I have a mod updated to 1.1, and 1.2 is an optional mod as per the modders choice. I don't want to deactivate update notifications on NMM in case the modder releases another update, so I could make a note saying something along the lines of "1.1 is current, 1.2 is etc" so that when NMM says 1.3 comes out, I can go look at it rather than forgetting that 1.2 is the optional mod.
I think it's an idea with some merit, and would help layer even more depth over some of the program's other clever organizational features.
Again, forgive me if this is already implemented in some way, or has been mentioned beforehand (I did look a little, but it was an idea I wanted to share before I got out to do my errands and such, so I wanted to get it out before I forgot).
Thanks for your work!