The title for the source of a piece of content.
tumblr.title contains the title of a post
tumblr.source_title contains the title of the content to which the post refers. You can use it for text, photo, quote, link, chat, audio, and video types and for reblogs. For likes and unlikes it is not populated.
- Filter for posts that refer to another post specified by its url:
tumblr.source_title contains "coffee"
Target service: Tumblr
Always exists: No