(under subclass 212) Aerostatic devices which are provided with means for forming indicia in the air by means of smoke or luminous material.
SEE OR SEARCH CLASS
222, Dispensing,
3+, for gas dispensers not specialized to skywriting, and see section 4 of the class definition of Class 222 for gas dispensing in other classes.
516, Colloid Systems and Wetting Agents; Subcombinations Thereof; Processes of Making, Stabilizing, Breaking, or Inhibiting,
1+, for smoke or fog colloid systems or agents for such systems or making or stabilizing such systems or such agents, when generically claimed or when there is no hierarchically superior provision in the USPC for the specifically claimed art.
