I am designing a book with a French "supplement" (partial translations). I was alerted by our French copy editor that traditionally, extra space (thin space) is used on either side of certain characters such as ";", "?", and ":". See: http://www.noslangues-ourlanguages.gc.ca/bien-well/fra-eng/typographie-t...
Does anyone know if this is still considered best practice, or, as I suspect, more of a formal rule that can be adjusted based on the specifics of layout and typeface choices.