Muted are those who can't use skills cause they are apanctured (Neji/Hinata) Immobilised (Shikamaru) etc. etc. In big shortcut, those who can't use their skills.

This works just in the same way as "high/low" float.. they can't make it universal :D
If so, then acupunctured enemies could be catched in shikamaru shadow... that's why they had to distingui* :p