Dunno if this is a bug, feature, or just my failure to comprehend.
If I go to the search page looking for (let's say) Sylas's post with a list of evidence for the constancy of radioactive decay, and type "decay" into the "Search Words" box and "Sylas" into the "Search by User Name" box and hit "Perform Search", "decay" is ignored and I get all posts by Sylas.
Is this the designed behavior? It appears to me from the way that the boxes are grouped on the page that it should search for messages by Sylas which contain the word "decay". If the behavior is as-designed, perhaps there should be a group of boxes for search terms, with a perform-search button, and another group of boxes for user name, with its own perform-search button. That would make it clear that you can't search for both user name and content in one search.