Deletion is the erasing of (at least) the phonological features of an element in a representation. In early versions of generative grammar, deletion was constrained by the principle of recoverability of deletion. In current work, recoverability is partly captured by the ECP. Deletion counts as a possible instantiation of affect alpha.
complementizer deletion (I know [that] he comes) may be an instance of deletion subject to the ECP.
- Riemsdijk, H. van and E. Williams 1986. Introduction to the theory of grammar, MIT Press, Cambridge, Mass.