A referential symbol indicates “particular or general categories of objects physical, social or abstract… Referential symbols have denotative meanings, meanings that link the symbol to its referent” (Nimmo, 1978, p. 68). On the other hand a condensation symbol is “a highly condensed form of substitutive behaviour for direct expression, allowing for the ready release of emotional tension in conscious or unconscious form” (Sapir, 1934, p. 493)
page 63 of Johnson-Cartee, K. and Copeland, G. 2010. Negative Political Advertising: Coming of Age. New York: Routledge.