One thing that some people don't know is that in some languages, nobiliary particles¹ are neither capitalised (unless they appear at the beginning of the name; i.e. when initials are omitted)² nor alphabetised. In Dutch, for example, *van*, *de*, *van der*, etc are ignored for alphabetisation purposes. In Flemish names, however, the particles are usually both alphabetised and capitalised.

**Example.** (Dutch) *B. L. van der Waerden* should be under W, not V. Another format³ would be *Waerden, B. L. van der*.

**Example.** (German) *C. L. F. von Lindemann* should be under L, not V.

**Example.** (French) *P. de Fermat* should be under F, not D.

**Example.** (Flemish) *M. Van den Bergh* is under V! Note also the capitalisation of *Van*, but not *den*. This is presumably because the V occurs at the beginning of the name.

However, it seems that sometimes theorems named after people with such names may or may not (presumably depending on the country) drop the particle altogether: e.g. *Fermat's little theorem*, *Lindemann–Weierstraß theorem*. In (modern) Dutch, you would never do this; e.g. *De Bruijn–Erdős theorem* (note that *De* is capitalised, since the initials are omitted).

**Remark.** I find it entertaining to see that some authors are aware of these rules and others aren't (or does it depend on their BibTeX setup?). Next time you try to find a name of this form in the references, take a look at how the author alphabetised it.

**Conclusion.** Every country has different conventions, and it's very confusing. However, the strategy of following what the author uses herself is a safe one.

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¹Their name is somewhat misleading: they do not always indicate nobility (e.g. in the Netherlands they don't).

²I believe that in German, the particle is omitted altogether if the surname is not preceded by the initials.

³This is the Dutch format. I don't know the conventions of other countries.