So CMS actually has a few pages just on this topic, beyond what Frank
and I recently discussed.
French and Spanish:
For last names only (or in sorting?) “de is often dropped. Its
occasional retention, in de Gaulle, for example, is suggested by
tradition rather than logic.”
But “La” or “Le” is not dropped.
German, Italian, Portuguese:
“In the original languages, particles … are usually dropped when the
last name is used alone. But if the form with the particle is the one
familiar to English speakers, it should be used.”
They include Humbolt, where they drop the “von”
particle is lowercased in full name, but uppercased in only last name
(or sort form?)
The prefixes (“al”, etc.) are typically consider part of the famly name.
“retained in indexing but are placed after the given name and preceded
by a comma”
Unfortunately, nothing about how this interacts with particles (which
Of course, this is all about rendering international names in English;
doesn’t cover other locales (though certainly may suggest them in some