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4.3 Numbering
Spell out numbers zero through nine in text. Use numerals for numbers 10 and higher. Defer to AP Style for rules on large numbers.
Phone numbers should use hyphens between the first set of numbers and the second set of number. No parentheses. Example: 210-567-7000. The lowercase letter “x” is acceptable for extensions. Example: 210-567-7000 x0000