Spell In general, spell out the name or term upon first mention and include the abbreviated form in parentheses right after the spelled-out version.
...
Don’t use periods in most initialisms.
AAD
CALS
CEO
LGBT
MArch
MEng
MFA
NY
PhD
RSVP
TBD
US
Washington,
DC
However, use a spaced period for initials in a person’s name.
A. D. White
Also, use a period in the abbreviated suffix of names, but omit the separating comma.
John F. Kennedy Jr.
Also, never abbreviate Cornell University in formal communications. Do not use CU, always spell out Cornell University.
For more related guidelines, see “names names of people.”