+
+ _type "playlist" indicates multiple videos.
+ There must be a key "entries", which is a list or a PagedList object, each
+ element of which is a valid dictionary under this specfication.
+
+ Additionally, playlists can have "title" and "id" attributes with the same
+ semantics as videos (see above).
+
+
+ _type "multi_video" indicates that there are multiple videos that
+ form a single show, for examples multiple acts of an opera or TV episode.
+ It must have an entries key like a playlist and contain all the keys
+ required for a video at the same time.
+
+
+ _type "url" indicates that the video must be extracted from another
+ location, possibly by a different extractor. Its only required key is:
+ "url" - the next URL to extract.
+
+ Additionally, it may have properties believed to be identical to the
+ resolved entity, for example "title" if the title of the referred video is
+ known ahead of time.
+
+
+ _type "url_transparent" entities have the same specification as "url", but
+ indicate that the given additional information is more precise than the one
+ associated with the resolved URL.
+ This is useful when a site employs a video service that hosts the video and
+ its technical metadata, but that video service does not embed a useful
+ title, description etc.
+
+