Downstyle is a copyeditors' term of art meaning a relaxing from prescriptive to descriptive usage, formal to informal, or standard written English, or strict, to casual. Standard versus downstyle. The term isn't in general usage, but is gaining ground among copyeditors due to its neutral valence. It's not perceived as negative or positive in most contexts. The first law for copyeditors is, as in the Hippocratic Oath, First, do no harm.

As Cheyne pointed out in the Spaces After Periods' thread, downstyle abbreviation punctuation omits internal punctuation, NATO, UN, EU, US, DC, LLC, PPC. The trend toward downstyle seems to be a product of newspapers and signmaking, where space being at a premium is a guiding principle. It probably started with acronyms having more than two letters, ATF, DOD, FBI, CIA, USSR, etc.

Downstyle capitalization probably started much earlier, perhaps as far back as Noah Webster's efforts to standardize and modernize American English conventions. Before the early 19th Century, standard capitalization style capitalized the initial letter in all nouns, proper or common. But styles were all over the place according to the whim of whoever dictated.

The serial comma experienced a downstyle also. The Chicago Manual of Style 14th Edition recommended downstyle, but reverted back to standard in the 15th as it had been in the 13th. Words Into Type, a style manual edging out Chicago in some publishing circles, recommends downstyle serial commas. Journalism style manuals recommend downstyle. Academic, scientific, and scholarly style manuals recommend standard.

The downstyle serial comma places commas between elements in a series when there's no conjunction following and none when a conjunction indicates the last of the series.
Downstyle serial comma: A, B and/or C.
Standard serial comma: A, B, and/or C.

In order to keep my clients' diverse style preferences in order, I keep a style sheet for each one, and each style rule that applies to each client depending on formality of the output and who their clients are. For example, a routine deposition of a civil litigation proceeding usually is in downstyle, but a legislative proceeding or legislative ceremony is in standard written English style including capitalized common nouns when they're related to the subject of discussion, i.e., Leadership, meaning the senior Legislators, Speaker, Whip, Minority.

Humorous copyeditor anecdote: redundonyms; redundant tautologies incorporated with acronyms.
ATM teller machine, automated teller machine teller machine
HIV virus, human immunodeficiency virus virus
PIN number, personal identification number number
UPS service, United Parcel Service service
ISBN number, International Standard Business Number number

But SAT test is not a redundonym, (another copyeditors' term of art). College Board, the parent SAT company, decreed in 1997 that SAT is a trademark and not an "initialism."

Something similar with The New York Times, The is part of the trademark.

There's a lot of little details to keep track of in copyediting work so that no one is inadvertently offended.