Since this site is about English usage, the standard search engine for the site which filters out "stop words" is going to be problematic since many of the questions on the site will be about stop words.
Obviously just eliminating the stop list isn't going to be a practical solution, but maybe there would be a way to allow indexing stop words if they are in quotation marks by themselves, or if they are italicized by themselves. In those cases, it is pretty clear that they are being use as words qua words and are contentful, and not as typical function words that deserve to be filtered out of search indexes.
