Who omits the 1 from the second number?! That is aweful!
You write pages 1,003–4, instead of typing out 1,003–1,004 which is just unnecessary.
Works the same with two digits, or even three: pp. 1,899–902.
This is standard practice and arguably clearer.
I've only ever seen it done with page ranges, though. I'm not sure if it's done with year ranges? E.g. 1984–5? Or 1989–92? You work with page ranges constantly in academia, I just don't see year ranges much in any form.
In speech, it's common, and misunderstandings are usually not a problem (if you're not monologuing on a recording) because someone will just ask; but in writing it looks like the range is the wrong way around. Maybe I expect more care in writing because the feedback loop is longer, or maybe it's just habit and I think it's wrong in writing because I never see it?
Quick, tell me how wide this range is, just as an order of magnitude:
285368737954–285368783645
Would be a lot easier if I only included the range at the end which had actually changed, wouldn't it?
That's why it's clearer. Now obviously that was an extreme example, but it's also easier to see at a glance that 1,387–9 is just three pages, as opposed to 1,387–1,389.
That's a change of about 50K, which isn't really that hard to notice.
"285368737954-83645" is... well I have to assume somewhere in the 10-100K range? Hold on a second while I line up the digits again... uh... let me rewrite that to "37,954 - 83,645", okay now I can read it. No, that wasn't any easier. I kept getting lost tracking where in the first number I was leaving off. Much easier to compare 737 vs 783 - digit groupings are really useful!
(I'll agree that 1387-9 is pretty reasonable, it just breaks down the longer the number is. Also, if the page count is important, you can just say "1387-1389 (3 pages)". This feels like the sort of shorthand you used to get on Twitter)
Genuinely trying to think of an examples, since e.g. books aren't ever that long and search results don't have that many pages (that you'd all read and refer back to). A salary range, perhaps, can get into the seven digits in extreme cases (not that you care about any individual digit when you make a lifetime's worth of money in a bit more than a year): "Prospective salary is 2'423'000 to 2'432'000" seems to convey the relevant info as well as "Prospective salary is 2'423'000 to 9'000" does (except that I wouldn't understand the latter and ask what this second number means, but that's plausibly attributable to me as an individual not being used to it)
Result:
> print pages in range from: 1, 003
> print pages in range to 4
Now have I have two errors to fix: page 1003 to page 1004. Not nice. Who formats like this?!
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Also, some RPG books or encyclopedias I own have chapter that span like this:
p. 630 to p. 70 (book 2)
To me, now is unclear, is that 70 with a reset page count, or 670 for book 2?
Since I just now learned that a quotation standard somewhere outside Germany exists that omits leading numbers, I now need to manually check where it ends.
TL;DR:
Don't make me think, and allow for automation. So just write on more number.
Or, sure, sometimes you get "285,368,737,954–285,368,783,645". But it's not like that's some kind of default. Except if you suffer from defaultism --- typically prefixed by "American".