machine-instance ⟨no arguments⟩ → description

description — a string or nil.

Returns a string that identifies the particular instance of the computer hardware on which Common Lisp is running, or nil if no such string can be computed.

 (machine-instance) 
→ "ACME.COM" 
or → "S/N 123231" 
or → "18.26.0.179" 
or → "AA-00-04-00-A7-A4"

The machine instance, and the implementation.

machine-type, machine-version