[Tagging] Test prep centres and cram schools as amenity=prep_school?

[Joseph Eisenberg]

I followed a link from amenity=school to amenity=prep_school, which
was only as stub with the text "Tutorial schools" and
description="Tutor school".

Taghistory shows it has been used since 2012, slowly increasing to a
few hundred uses since 2018, but had no wiki page still March 2019.

However, I found out that this tag has now been added to
osmlab/name_suggestion_index for brands like Kumon - an East Asian
test prep centre, aka "cram school".

Unfortunately, this usage does not at all match the UK or US English
meanings of "Prep School":

1) "Prep school": in the UK, a private primary school for children,
especially boys, between the ages of 7 and 13, who will then usually
go to "public school" (a type of private secondary school). See
https://dictionary.cambridge.org/dictionary/english/prep-school

2) "college preparatory school", informally "Prep school" (North
American English), a type of secondary school where there students
plan to attend University. See
https://dictionary.cambridge.org/dictionary/english/preparatory-school

I couldn't find any definition of "prep school" which mentioned test
prep centers, as in this wikipedia article:
http://wikipedia.org/wiki/Test_preparation - perhaps it's Singaporean
or Hong Kong English, or a translation error?

So, what's a better term for a test prep centre, cramp school, or
tutoring office? There the rarely used tag office=tutoring, but that
doesn't quite cover a place like Kaplan or Kumon -
https://au.kumonglobal.com/ - https://www.kaptest.com/

amenity=test_prep
amenity=cram_school
office=test_prep
amenity=tutoring

Other options?

-Joseph