This is a programming website. It's expected that there will be many keywords that are composed of underscores. Often, the keyword is pretty specific whereas the individual words are not. (For example, the word
meta could be for anything while if I'm searching for
_meta I'm probably looking for a question about Django records).
Considering how central underscores are to many programming languages, and considering that I can think of few occasions where someone would accidentally type an underscore between two words they were trying to search for, I'm wondering why ignoring underscores seems to be default behavior.
If it's an implementation issue I understand, but for usability I'd rather be told that there were no questions with my underscored keyword, if that is the case, and be given the opportunity to search for the words split out by spaces.