Actually over 1200 hits searching MVNO on forums here.
It does seem to occasionally cause confusion.
I remember in early 21st C reading a trade/professional Telecomms journal after a few years break and finding every article had myriads of undefined acronyms and abbreviations.
Given that this is a Tech site, I'm only partly sympathetic, which is why I bothered to explain.
Then there are acronyms like CAPI and SMB that change with time or context to mean something entirely different. Or BEREC, which in 1906 was British Ever Ready Electrical Company and in 1950s was British Ever Ready Export Company (a UK Ever Ready Division) and in 1980s briefly BEREC was the holding company for Ever Ready and BEREC.
BEREC is now:
Body of European Regulators for Electronic Communications (BEREC) was established by Regulation (EC) No 1211/2009.
Very annoying when searching for 1950s BEREC as there is really no sensible way to to date related searches, either on content or site creation.
It's nearly impossible to keep up to date. Maybe articles should mention once, what the abbreviation is for?