sbeigel/NSAttributedString-Additions-for-HTML — comment on commit 19f65cfcb6e36b755806afe12e84f4c2c9699e16
File:  line 0
By Cocoanetics:

I would reverse the order: there should always be a style sheet with default styles. If one is passed as option then this should be merged into the default one so that non-overridden styles are preserved.