Curious record side labeling


Do any of the jazz gurus on here know why some double-set records have this curious side labeling where record 1 has sides A and D, and record 2 sides B and C? It does not make much sense to me, and I wonder what purpose it serves other than to confuse the listener. I noticed this with a couple of Coltrane records from the '60s, recently with "The Other Village Vanguard Tapes."
actusreus
It's really amazing me that this is such a surprise! I guess I'm showing my age.

Normal people who played records back in their heyday wanted some level of convenience. Automatic start and stop and record changers in particular were the norm by far. Most were very cheap and made for mass consumption, but that was the norm. Dual is the only brand I recall that made decent quality changers. I still have mine, a Dual 1264 in my second system. It is serviceable but not up to snuff for most audiophile vinyl affectionados. I do not recall any changers that were much better. CDs took convenience to the next level. Now, music servers take it further. And performance need not suffer along the way.
Mapman, I grew up in the '70s and early '80s way before the CD era and LP changers were not the norm, at least in Europe. In fact, I didn't even know they existed until this thread. Juke box changers, sure, but not products for individual use.
Act,

There is a nice article on record changers on wikipedia. It seems to
indicate changers bdcame common in the us from the 50s through the
seventies with bsr dominating the market. Thats consistent with my
recollection growing up during that time. Convenience of cds did them in
though single play manual turntables obviously survived. Dual, garrard
and telefunken made changers in europe it seem but perhaps less
common there than in us brand console and integrated systems that were
quite common back then. Bic was another popular mid fi brand that
made changers that took mm cartridges. Most bsr and similar mass
produced changers took lower performance, high tracking force ceramic
carts that were responsible for a lot of wear on many records in us homes
back then.
When I first got into the audio business, one of my stores sold a really nice Technics changer. It was actually a pretty decent table. We also sold the BIC and Dual.