Answer:

reg

Answer	Crossword Clue
REG	Gas pump abbr.
REG	Like some gas: Abbr.
REG	Std.

REG	Neither long nor short: Abbr.
REG	Gas type: Abbr.
REG	Gas option: Abbr.
REG	Agcy. issuance
REG	Rule laid down by a commission: Abbr.
REG	Short order?
REG	Coffee order: Abbr.
REG	Nothing special: Abbr.

REG	Pump option: Abbr.
REG	Elton John nickname
REG	Suit size: Abbr.
REG	It's less than premium: Abbr.
REG	Lower-priced gas option: Abbr.
REG	Pump abbr.
REG	Lowest-priced gas grade: Abbr.
REG	Govt. agency creation

REG	Quick rule?
REG	Gasoline choice: Abbr.
REG	... U.S. Pat. Off.
REG	Not long or short: Abbr.
REG	Gas station abbr.
REG	Brief rule?
REG	Brief rule
REG	Coffee size: Abbr.

REG	Avg. size
REG	Avg.
REG	Kind of gas: Abbr.
REG	Ordinary size: Abbr.
REG	I.C.C. issuance: Abbr.
REG	Not spec.