Niel,
My thoughts are ornamental on the polearms, though in motion and martial use the tassle which sits in this hole may have a martial application like the tassle on the Jian, but you'd have to ask practicioners of the Yan Yue Dao to confirm this.
http://www.vikingsword.com/vb/showth...hinese+halberd
http://thomaschen.freewebspace.com/photo4.html
Gav