Pop (& Nick)

International Mechanical Code:

Section 913.2 Exhaust Required. Clothes dryers shall be exhausted in
accordance with Section 504.

Section 504.4 Exhaust installation. Dryer exhaust ducts for clothes
dryers shall terminate on the outside of the building and shall be
equiped with a backdraft damper...... Clothes dryer exhaust ducts shall
not be connected to a vent connector, vent or chimney.

See also sections 504.5, 504.6, 504.61, 504.62, 504.7.