This is pretty self-explanatory, but some of Bing's search operators, specifically using the - to remove certain terms from search (as this operator was intended - see the instructions here for explanation of the "-" operator).
I f the operator "-" doesn't RELIABLY and PREDICTABLEY work in practice, and is so easily broken that it's essentially non-functional, or does the opposite of what it is intended to do, why is it even included or suggested for Bing search?
To replicate this strange behavior, simply search for something in Bing, and use the "-" operator to omit a term from the search (not this applies to most Bing operators, I'm just singling out "-" because it's reliably broken). One of a few things will probably happen:
- You will get the term included in the search results anyway, even though you used "-" as suggested.
- You will get search results with the term prioritized over other results.
- If you're extremely lucky, it might work for a minority of searches, though this is extremely rare.
Example screenshot:

I want to use Bing search, I really do, but I have to use Google instead of Bing search because Google's search operators work as expected every time, all the time, reliably.