That's a very BIG NO NO NO NO NO NO NO. What a bad argument! Bad, bad, bad, bad, bad, bad, bad, bad, bad. Besides, no one uses double spacing today (except stubborn engineers trying to enforce standards from the 1960s that don't make sense anymore).The two spaces only appear after a period that terminates a sentence. Not after one for an abbreviation. That is how you tell the two cases apart.
1 case in Dutch that I know is a postal code followed up by a town name on a letter or package. No idea where it originates from but it's done a lot. It may have to do with the code format xxxx yy that contains a space itself but should be considered a word. The parts separated have no meaning. Maybe a space is added after it for clarity. because there should be no period.Sometimes, engineers think they are smarter than everybody else and end up making very silly decisions. The fact that POSIX standards define the end of a sentence as needing two spaces after the period is asinine, regardless of the technical reasons that may have led to such a conclusion. In English and in any other language that uses the Roman alphabet you never use two consecutive spaces for anything, let alone after a period. Thanks to this genius decision, one cannot navigate or operate on real sentences when editing a common text file in nvi. This opinion is not mine, but God's, who has decided to reveal it to me, so don't even try to contradict it or justify the standard.