Personally I use the word "MEOW" because
a) it's easy to search for and spot in logs
b) it will (hopefully) never be a legitimate string in the kind of things I work on
c) fairly unlikely to cause offence (unless the customer is a dog)
> The header of the marshaled object reference begins with a distinguished signature (‘MEOW’)⁶ [...].
> ⁶ A Microsoft Program Manager who shall remain anonymous claims that MEOW stands for Microsoft Extended Object Wire representation. The author, while somewhat gullible, is skeptical of this story but is willing to give the aforementioned source the benefit of the doubt.
— Don Box, Essential COM
Now, when I'm not required to use some other name, I tend to name my error handlers "hope".
(alt text: vintage meme depicting two dogs using a computer, captioned ‘On the Internet, nobody knows you’re a dog.’)