Flag and Banner Bidirectional Symbols

A flag or banner is a bidirectional symbol, with a straight part for upward flow and the wavy shape of the flag, sometimes S shaped, or helical, is the downward flow.

The opposite polarity would be upward flow, the tree on image B, the two fingers handsign on image C, and the distal key on image D. The center flow path is also bidirectional, on image A and E.