My Name
My surname is von Briesen - two words, lowercase v, and both words together make the name. Not "Briesen." Not "Von." The whole thing.
What the von Is Doing There
Von is German for "of" or "from," and in a surname it originally pointed at a place - the family of, or from, Briesen. It behaves like a preposition rather than a name, which is why it stays lowercase in the middle of a sentence and why it doesn't stand alone. "Mr. von" isn't a name; it's half a preposition.
Where it gets interesting is what computers do with it. Alphabetize me and you'll find me under B in one system, V in another, and occasionally under a space in a third. Ask a form for my last name and it will frequently take "von" as a middle name, or eat the space, or capitalize it against my wishes. I've been Vonbriesen, VON BRIESEN, von briesen, and - my favorite - Briesen, von D.I., which is a real person somewhere in a state database.
Read This Too
My colleague Dr. Manuel A. Pérez-Quiñones has written the definitive page on Hispanic surnames, and it makes the point better than I can. Hispanic naming uses two apellidos, the father's first surname followed by the mother's, and neither one is a middle name, a hyphen accident, or optional. His page walks through how that works across generations and what organizations should do about it.
We arrive at the same place from different directions. His name has more information than an American form expects; mine has a word the form doesn't know what to do with. In both cases the software is confidently wrong, and in both cases the fix is the same: store what the person tells you, print it back the way they gave it, and stop assuming everyone's name has exactly two parts with capital letters at the front.
This matters in a web-development course for a practical reason. When you build a form, you decide whose names fit in it. A single "Last Name" field with a capitalization rule is a decision, and it excludes people. Ask for the whole name, let them type it, and show it back exactly as they wrote it.
And the con
On my ITIS 3135 site I sign the header con von Briesen. That isn't a typo and it isn't my first name. Con is "with" in Spanish, as in con queso, and set next to von it makes a small joke in two languages at once: with-of Briesen. It also gives students a first lesson in reading a name carefully before assuming they know what it says.