Title Search vs Keyword Search: The Craziness of ?title_type= And ?genres=

The two primary Search programs on IMDB.com are Title Search and Keyword Search. These are distinctly different pieces of software, written by different people, but perform largely the same function as one another.  The parameters they accept are largely the same, and the records they display are largely the same.  There are a few distinct differences, and I'll get to them.But I want to point out one big old glaring difference between the two.  Under a Title Search a Feature Film is known as a "?title_type=feature", while under a Keyword Search a Feature Film is known as a "?title_type=movie", and they always a different number of results.  They are not different names for the same thing.Let me start by showing this bit of deconstruction of the two search engines, and two prominent variables they accept.https://www.imdb.com/search/title/?title_type=&genres=keywords= title_type= feature video short documentary video_game tv_movie tv_special tv_short tv_series tv_miniseries tv_episode (also accepted inputs from Keyword Search): movie videoGame tvMovie tvSpecial tvShort tvSeries tvMiniSeries tvEpisode genres= action adult adventure animation biography comedy crime documentary drama family fantasy film-noir game-show history horror music musical mystery news reality-tv romance sci-fi short sport talk-show thriller war western (adult and short are not advertised in the advanced search.) https://www.imdb.com/search/keyword/?title_type=&genres=keywords= title_type= (CaSe SeNsItIvE) movie video short videoGame tvMovie tvSpecial tvShort tvSeries tvMiniSeries tvEpisode (Title Search inputs are NOT accepted): feature documentary video_game tv_movie tv_special tv_short tv_series tv_miniseries tv_episode genres= (CaSe SeNsItIvE) Action Adult Adventure Animation Biography Comedy Crime Documentary Drama Family Fantasy Film-Noir Game-Show History Horror Music Musical Mystery News Reality-Tv Romance Sci-Fi Short Sport Talk-Show Thriller War WesternSo you can use this as a quick reference guide to the lay of the land between these two searches.  By and large they are identical, but strangely, Keyword Searches cannot search for objects with a Title Type of Documentary, nor does it return the same list of Feature Films (=movie) that a Title Search displays for Feature Films (=feature). As you can see, besides the fact that a Keyword Search requires its variables to be Case Sensitive, with a slight difference in variable naming convention... much of the rest of these search functions are identical. The results from a Keyword Search displays a larger thumbnail, and a Refine Search box, while the benefits of a Title Search is the ability to return 250 results per page instead of just 50 (&count=250), and a few other minor details. But what I really want to identify is the difference between a Feature Film "feature" and a Feature Film "movie" as they are defined between these two different search engines.  Most films overlap between these two categories, while 10 to 20 percent do not. Anyone?