Full Idea
There are pure, Fregean, abstract, de dicto propositions, in which a compositional structure is filled only with senses; there are pure, Russellian, concrete, de re propositions, which are filled with referents; and there are mixed propositions.
Clarification
'De dicto' concerns descriptions; 'de re' concerns objects
Gist of Idea
There are Fregean de dicto propositions, and Russellian de re propositions, or a mixture
Source
Paul Horwich (Truth (2nd edn) [1990], Ch.6.31)
Book Reference
Horwich,Paul: 'Truth (2nd edn)' [OUP 1998], p.91
A Reaction
Once Frege has distinguished sense from reference, this distinction of propositions is likely to follow. The current debate over the internalist and externalist accounts of concepts seems to continue the debate. A mixed strategy sounds good.