NGS Style Manual‎ > ‎- D -‎ > ‎

da, de, d', du, la, van, von

Capitalization of particles such as de, du, la, von, etc., varies, depending on the preference of the individual.  If this cannot be ascertained, lowercase the particle (except for La, Le, Les in French names) with the full name or surname only except at the beginning of a sentence.

Do not allow a line break to separate the particle from the surname that follows. Occasionally the particle is dropped entirely.

In some cases the particle is dropped when the surname is used alone:
          Paul von Hindenburg, Hindenburg
           

Vasco da Gama, da Gama
Charles de Gaulle, de Gaulle
Comte de Grasse, de Grasse
Michel de Montaigne, Montaigne
Marquis de Montcalm, Montcalm
Duc de La Rochefoucauld, La Rochefoucauld
Hernando de Soto, Soto (academic usage), de Soto (popular usage)
Irénée du Pont
Ludwig van Beethoven, Beethoven
Vincent van Gogh, van Gogh
Wernher von Braun, Von Braun
Friedrich von Schiller, Schiller