A consensus for the .0001 bitcoin, could evolve from the terminology around basis points. Without adding any new nomenclature, a bitcoin moving one basis point moves 0.0001 bitcoin = 1 btc bp. One basis point is a pip. So, 1 bitcoin pip = 0.0001 btc = 1 btc pip = 1 btc basis point = 1 btc bps.
One could consider names:
.0001 bitcoins = bitcoin pip
.0001 bitcoins = btc pip
.0001 bitcoins = bit pip
"Bitcoin pip" is not a new identifier since a pip is already defined as 1/100 of 1%, and "Bitcoin pip" describes a pip, not a type of bitcoin. Besides, if "Bit pip" were to work as new nomenclature, then bp would be the abbreviation which already means basis point.
That is the context for proposing that a 1 basis point move, a bitcoin pip, be called a pip bit = 1/100 of 1% of 1 bitcoin = 1 pbit = 1 pb .
PS - How do I modify the site's spell checker to accept the word "bitcoin" as a correct spelling? (by modifying my browser's dictionary)