Back In The Day (mid 70s) I was doing a design based on the Z80 stuff.
Someone doctored up and circulated several of the relevant datasheets.
Among the japery therein was :
JGL - Jump and Get Lost
BGR - Branch for no Good Reason
SBW - Shift Both Ways
SSP - Sharpen Stack Pointer (After much use, they apparently get dull)
RWO - Registers Write Only
CRA - Convert to Random Address
IBD - Interpolate Data Bits
CSR - Context Sensitive Reset
and my personal favorite
POF - Power On Fail
The data sheets also had numerous other little details... one I liked
was the address line's rise-time called out as: "6:45 AM, Mon -> Fri"
Cheers
John