Rhematic Sign or Rheme is a term coined by Charles Peirce to denote a specific type of sign. A sign that has as its interpretant a quality ability (CP 2.250).
Peirce distinguishes the trichotomy rheme, dicent, and argument by relating the sign to the nature of its interpretant.
This trinity classification, albeit roughly, corresponds to the more traditional trichotomy of concept, message, and argument.