Need a better way to select which stylesheets to process

[joyously]

I'm looking for a way to reverse the default of handling all stylesheets except those with data-no-prefix.
I would like to be able to ignore all except the ones I mark, without changing too much.
This is because I'm using this in an environment where I control only a small part of the total CSS loaded.

[LeaVerou]

There is currently no such way, but I wouldn't oppose a PR for it.
I agree that since the need for prefixfree has diminished since it was first written in 2012, this would be a useful addition.

I'd suggest an HTML attribute like "data-prefixfree-opt-in" that can be placed wherever and makes -prefix-free opt-in instead of opt-out. Then, data-prefix on stylesheets to process them.