X Y Z

X-ray (n., v., and adj.)

year-end (adj.)

yearlong

years
Use figures without commas: 1986. Use s without an apostrophe to indicate spans of decades or centuries: the 1890s, the 1800s. Years are the lone exception to the general rule in numerals that a figure is not used to start a sentence. Also, see dates or academic years.

ZIP code
Use all caps ZIP for Zoning Improvement Plan, but always lowercase the word code. Run the five digits together without a comma, and do not put a comma between the state name and the ZIP code: New York, NY 10020.