If a tiddler has a <<.field caption>> field, this is shown instead of the tiddler's title. If the caption field is empty, a blank entry is shown.
Note: Each first [[step|Filter Step]] of a [[filter run|Filter Run]] not given any input titles receives the output of <$link to="all Operator">[all[tiddlers]]</$link> as its input. This means all the existing non-[[shadow|ShadowTiddlers]] tiddlers.