What means show replies checked to false or to true ?please help in example

raffi01061993 · 2014-02-04T07:32:26.000Z

what means show replies checked to false or to true ?please help in example

vincentisambart · 2014-02-04T07:54:00.000Z

Replies are tweets starting with @

niall · 2016-02-06T05:27:12.447Z