Apart from the language unity in both countries, there is, however, one distracting anomaly in dealing with the Dutch and Flemish family names.
In Belgium, one has chosen not to modernize the family name in contrast to the Netherlands. For example, a commonly appearing family name both in BE and NL is "Verbeeck" (Flemish spelling dating back to the Middle Ages), or "Heijndrickx" while "Verbeek" and "Heindriks" in NL spelling. Another example concerns our name, "Van Mieghem" and many others that use the word "van" (= "from"), or "de" (= "the") as well as derivatives like "van der", "der", and others. In BE, these words are regarded as integral part of the family name. Consequently, they are written with capitals and alphabetically ranked under the "v" or "d". In NL, these words have a lower priority; they are not written in capital, and ignored when placed in alphabetical order. Hence, in BE, my name is written as "Piet Van Mieghem", and in any telephone book, you may have found my name under the "v" (while I was living in BE) as "Van Mieghem, Piet". I have an NL namesake, whose name is written as "Piet van Mieghem" and you may find him in a Dutch telephone book under the "m" as "Mieghem, Piet van". However, when addressing the person in NL, such as "Geachte heer Van Mieghem", a capital "v" is used, while in BE, it is capital "Van" always and everywhere.
Most of us take pride in our name. Since even in Flanders and in the Netherlands, most people simply do not know that there is a difference, my name in the Netherlands is, unfortunately, often incorrectly written. There are some situations where a misspelled name is rather unpleasant. When entering the USA some months after 9/11, my flight ticket (bought in the Netherlands), showed the name as Mieghem, P. van, while my passport stated Piet F. A. Van Mieghem. Perhaps, you may image the sweat (and almost tears) to convince over-suspicious US officials.
Second, when a Belgian has served his country in a most extraordinary way, the Belgian King may decide to raise that citizen into the ranks of the nobility. As a token of appreciation, he may bear the title of baron (or some other noble title) and, in correspondence with the French tradition of the "noblesse", the small words like "Van", "De", and the like are changed into small letters. For example, the founder and first president of the Interuniversity Micro Electronic Center (IMEC), the late Professor R. Van Overstraeten has received the title of baron, and since then, his name was written as Professor Baron R. van Overstraeten.
It is unclear to me what rules non-native Dutch follow when they spell Dutch/Flemish family names. For example, most people know the great German composer, Ludwig Van Beethoven, whose grandfather lived in Mechelen (near Brussels, BE), but many call him just Beethoven, or van Beethoven (like Wikipedia) or even von Beethoven. When referring to a paper co-authored by my colleagues Remco van der Hofstad (who is Dutch), Gerard Hooghiemstra and myself, the correct reference is difficult to explain to non-native Dutch because it should be "R. van der Hofstand, G. Hooghiemstra and P. Van Mieghem" and alphabetically sorted under the "h", while if I am the first author, we reside under the "v". Moreover, the name "Van" seems a first name in the USA, an other source of confusion: some authors refer to me as P.V. Mieghem.