The herbs in this category are neutral or warm. They are used mostly for cold phlegm, phlegm-dampness, or phlegm in a neutral environment, without the presence of heat.  However, they are sometimes used even for the treatment of phlegm-heat (when combined with cooling herbs), because their acrid, warmer natures make many of them very powerful drying herbs for eliminating phlegm.

Also consider, as appropriate: herbs the resolve phlegm-heat, herbs that drain dampness, herbs that warm the interior, herbs that promote Qi and blood circulation, herbs that release the exterior, herbs that stop coughing and wheezing, etc.