This paper explains how an assertion may be understood despite there being nothing said or meant by the assertion. That such understanding is possible is revealed by cases of the so-called ``felicitous underspecification'' of demonstratives: cases where there is understanding of an assertion containing a demonstrative despite the interlocutors not settling on one or another object as the one the speaker is talking about (King 2014a, 2017, 2021). I begin by showing how Stalnaker's ( 1999) well-known pragmatic principles adequately permit and constrain the felicitous underspecification of demonstratives. I then establish a connection between the satisfaction of Stalnaker's principles and understanding, and show how that connection sheds further light on the relevant cases. After developing and motivating my proposal, I address some objections to it, then briefly discuss the felicitous underspecification of expressions other than demonstratives alongside contrasting my proposal with a similar one from Bowker (2015, 2019) that concerns definite descriptions.