People who use Scheme but not Common Lisp often use "Lisp/Scheme" as a
blanket term to cover things related to their Scheme
programming. "Come out to the Lisp/Scheme meetup! Check out this new
Lisp/Scheme blog! Here's a reference for Lisp/Scheme style!" Common
Lisp users don't do that very much; when they mean Common Lisp they
say "Common Lisp." "Lisp/Scheme" has started to sound like a very
fuzzy term, and whenever someone mentions it I wonder if they actually
do any substantial programming in either Lisp or Scheme.
See lisp for examples.
When people learn Scheme, it's very exciting and meta, so they
often enthusiastically start implementing their own Scheme. It's a
good "enthusiastic Scheme newbie" tip-off if someone says they're
writing their own Lisp. Fewer people, on learning Common Lisp, get all
excited and decide to write their own.