Fanion

from WordNet (r) 3.0 (2006)

fanion
    n 1: a small flag used by surveyors or soldiers to mark a
         position

from The Collaborative International Dictionary of English v.0.48

Fanion \Fan"ion\, n. [See {Fanon}.]
   1. (Mil.) A small flag sometimes carried at the head of the
      baggage of a brigade. [Obs.]
      [1913 Webster]

   2. A small flag for marking the stations in surveying.
      [1913 Webster]