Definitions of "Zero Bugs"

I am writing in response to this tweet:

@arlobelshee @moshjeier @jaybazuzi @lisacrispin @dwhelan I agreed for some def'n of terms. Please link to your def'n of those terms.

— mheusser (@mheusser) April 11, 2016

A common definition of "Bug" is "Code that does not work according to spec." I see this as a deliberately narrow definition to cope with (coddle!) too many bugs. I want to come back to that, but first some definitions of Zero:

• The normal known bug count is 0. Switch from counting bugs to counting days/months between bugs.
  
• For every bug we've ever seen, we know that that class of bug will never happen again.
  
• We no longer need a find-and-fix cycle before shipping a feature.
  
• A mindset shift, from "bugs are inevitable" to "bugs are, uhh, evitable".
  
• An ideal to aim for, which informs how we work each day.
  
• A state where the rules of the game have changed, and we discard the protocols and cautions we had put in place to manage bugs.

As we approach Zero, you can change your definition of "Bug" to:

Anything surprising, confusing or disappointing anyone.

— Arlo Belshee (@arlobelshee) April 11, 2016

Are any of these definitions the same as "no customer will ever find a bug in this code, ever"? No, but that hardly matters. You certainly shouldn't let that be an excuse to argue that Zero Bugs is impossible instead of deciding to start down the path to #BugsZero.