A closely related problem: the concept of making the text "fit" in the target language. A reference to a historical figure, a popular TV programme, a football club, a town... these may mean nothing in the other language. Another tradeoff. Do you explain the details, and lose the spontaneity, or do you substitute a reasonable equivalent? Even translating the Milieuwet as the Environment Act may not be appropriate, for example, in another country where their own environmental legislation is entirely different. Calling it the Dutch Environment Act may be more sensible.
Dates and numbers
Seemingly minor items such as numbers and dates may need a little attention as well. To English speakers 1,500 is fifteen hundred, but to many contintental Europeans it would be one and a half. Purely numeric dates are generally MM/DD/YY on the American side of the Atlantic, but DD/MM/YY in Europe (we prefer alphabetic codes for the months to avoid the potential confusion). A sum of money would never be expressed as £ 5,= in English (it would be written £5 or £5.00). And so on.
Addresses and phone numbers
You may also find us altering the formats of postcodes or telephone numbers, even. There is a convention used in much of Europe by which a country code can be prefixed to the postcode, but that is not done in Britain. Neither are slashes or dots ever used when writing telephone numbers in English. And of course, the international dialling prefix may need to be added, if you are expecting people to call you from the target country. Maybe the postal address is one where the recipient pays the postage (Freepost in the UK, an antwoordnummer in NL) - but that doesn't apply for international mail. Similarly, premium rate phone numbers may not be accessible from abroad. Naturally, these types of things have to be taken into account as well.
People are naturally very proud of their academic achievements and titles and may want them stated in their communications. This is however not as easy as it might seem. The multiple titles of the German professor above have to be condensed to just the highest one, in normal English usage. Others may have no good equivalent: the Dutch Ing. and Ir. and drs for example go before the name, but are meaningless and therefore confusing in English and have to be either dropped or have a rough equivalent instead, e.g. a BSc or MSc (British - BS or MS to the Americans) after the name. The Ir. title in particular looks like a first name, to any English-speaking reader who is familiar with the Continental habit of sometimes placing two letters such as "Ph." for Philippe or "Th." for Theodorus... (which incidentally also have to be just "P." and "T." respectively in English). The most confusing one of all, perhaps, is the Dutch law degree (LLB or LLM after the name in English) that entitles you to a mr. in front of your name... even if you're a Mrs!