I recall early in my membership with THS, while reading through the website, that if asked at the border, to always reply that we are entering the country for travel purposes. If further questioned about location of accommodation, to have the name and address of the homeowners handy to provide. We consider the HO to be our friends, and would simply state staying with friends. None of these situations have occurred, as we rarely fly during our travels. Interestingly enough, and to our surprise, official border crossings (and customs) while traveling from country to country on a bus or train, and sometimes even a car, seem to be nonexistent.