The way it currently is worded:
Zero score accepted answers: more than 10 and 25% of total.
But this does not actually match when the badge is actually rewarded. As can be seen from this data query written by A. Rodas, there are a handful of users who have the badge even though they have exactly 10 zero score accepted answers, i.e., not more than 10.
The badge behavior should match the description. That part of the description would be correct if it had the following format.
Zero score accepted answers: (10 or more)|(at least 10)
And while we're at it, I think the last phrase should be reworded as well. The phrase "25% of total" literally implies exactly 25%, whereas the badge is rewarded when it is at least 25% of the total. It would be clearer if it was reworded to something of this format
Zero score accepted answers: (10 or more)|(at least 10) and (25% or more)|(at least 25%) of total.
Finally, what does "of total" mean? Is it the total number of accepted answers you have, or is the total number answers you have? (answer: accepted answers) The badge would be more correct and less ambiguous if it was reworded thus
Zero score accepted answers: (10 or more)|(at least 10) and (25% or more)|(at least 25%) of total number of accepted answers.
or perhaps even totally reworded, like this:
at least 25% of all accepted answers, with a minimum of 10, have a score of zero.
And of course, if you have a better way to reword it, please suggest it.