@sindarina thanks for the reminder! And it's also valid for phone numbers! Most countries have ranges of phone numbers dedicated for cultural usage (movies, for example). Phone numbers that will never be attributed to a person or a company.

For France, for example, any 10-digit starting with 01 99 00, 02 61 91, 03 53 01, 04 65 71, 05 36 49 or 06 39 98 (replace the initial 0 by +33 for international use)

(Legal source: https://www.legifrance.gouv.fr/jorf/article_jo/JORFARTI000037263033)