More humorous is that it's not usefully "standard" even within the product from that one company.
The core Office applications pre-date Unicode on Windows, and accordingly they have their own esoteric idea of what the relationship is between what the user types, what appears on the user's screen and what should be saved in the document file.
This is most obvious when moving documents between a Mac and a PC, but it happens between PCs as well.
Likewise the spreadsheet "standard" leaves a bunch of things undefined, this was more obvious back when actual real users sometimes had different families of CPUs, but it remains problematic for financial and scientific work where it often turns out that the are undocumented restrictions on the accuracy or repeatability of calculations.
AFAIR the outcome of all this was that Microsoft has itself simply declared that the de jure standard mentioned above is a figment of people's imagination. Only a subset of Office document features are actually supported meaningfully, most of the documents you receive are the MS Office equivalent of foo(x++, x++, x++); in C.