data—plural, but may be used with singular verb. (American Heritage, Third Edition)
database (American Heritage Dictionary, Third Edition)
dates—In news releases and Staff Notes, use the standard American system for dates: month-day-year. Example: January 30, 2004. Note the comma. In the Quarterly, use the international system: day-month-year. Example: 30 January 2004. No comma. For PSAs, write as the announcer will speak it: January 30th, 2004. See also "years."
DC—direct current; always abbreviated
decision maker, decision making—noun; Wallace was always involved in decision making. Hyphenate as preceding adjective: decision-making activities. Now also consistent with "policy maker." [12/01]
decimals—Use 0 before the point, except in statistical correlations (and even there if it would look peculiar, e.g., use -0.45, not -.45).
degrees—use the degree symbol closed up: 30°N (in nontechnical writing, 30° north), 30°C. Do not use degree symbol for Kelvin scale: 280 K. See also "Kelvin scale." Always spell out first use in news releases: minus 40 degrees Fahrenheit.[updated 12/01]
degrees, academic—Bachelor of Arts degree, but bachelor's or master's degree or doctorate (lower case); B.A. or M.A. or Ph.D. in music history. Either initials or spellouts are fine on first use.
deice—no hyphen. [12/01]
design, logo—see "logos."
Dicomed—the manufacturer; initial cap only
dictionary—Currently, we follow (in this order) The American Heritage Dictionary, Third Edition. As supplements, use Webster's Third New International Dictionary and McGraw-Hill Dictionary of Scientific and Technical Terms. We use Webster's Instant Word Guide for syllabification.
direct current—DC (always abbreviate)
directors (laboratory vs. NCAR associate)—see "Associate directors, NCAR."
disclaimer—See "sponsorship statement."
disk—not disc, except for compact disc (which is an industry-wide spelling)
distributed-memory shared-multiprocessor architecture. Hyphenate this way. [09/00]
division—when writing out MMM and CGD, capitalize the "d" in divison even though that word is not in fact part of the acronym. Example: "The Mesoscale and Microscale Meteorology Division has just hired three new employees."
domain name system—not capitalized
Doppler—always has an initial cap.
downwind—takes "from," not "of"
D-region, D1-region, D2-region (also E- and F-regions and layers)—all hyphenated
dry line (noun); dry-line (adj.) [08/01]