The discussion of computing percentages using WITHIN reminded me of another almost superseded/little used piece of syntax that can be useful (if you need it of course).

TABLE FILE CAR
PRINT COUNTRY CAR AND COUNT
BY COUNTRY SUBFOOT
"THERE ARE <ST.COUNT CARS IN <COUNTRY"
" AND <TOT.COUNT CARS IN THE WORLD"
END

The COUNT (which can have NOPRINT) is just that, a count of CAR within a COUNTRY. AND is for readability only.
Another example:

TABLE FILE CAR
SUM CAR NOPRINT
AND COUNT NOPRINT
AND COMPUTE CARPCT/F5.2%=(COUNT/TOT.COUNT)*100;
PRINT CAR
BY COUNTRY
ON COUNTRY SUBFOOT
WBY COUNTRY SUBFOOT
"THERE ARE <ST.COUNT CARS IN <COUNTRY"
" AND <TOT.COUNT CARS IN THE WORLD"
END

What the COUNT brings in is the ability to use TOT.COUNT at COUNTRY level.

There must be many other pieces of forgotten syntax. Anyone remember others?