We have a winner. Tmeatzie correctly noted that early on Windows 95 bore the codename "Spokane." Our sources, who worked at the Redmond company, say the name lasted a short while, replaced by the official codename "Chicago."
We gathered up this other odd little tidbit in our research: all the rest of this explanation is taken from the Wikipedia entry on Apple Inc. litigation.
Apple complied, but engineers retaliated by changing the internal codename to "BHA" for "Butt-Head Astronomer". Sagan then sued Apple for libel. The court granted Apple's motion to dismiss Sagan's claims and opined that a reader aware of the context would understand Apple was "clearly attempting to retaliate in a humorous and satirical way, adding "One does not seriously attack the expertise of a scientist using the undefined phrase 'butt-head'."