Gamma-marking
Gamma-marking is a mechanism which assigns the feature [+gamma] to empty categories that are properly governed. For chains terminating in an argument position, it is assumed that gamma-marking takes place at S-structure, while for chains terminating in a non-argument position it is assumed to take place at LF. EC's that are not properly governed receive the feature [-gamma] by default. In this way, applying the ECP means checking whether an EC has the feature [+gamma] at LF.
Link
Utrecht Lexicon of Linguistics
References
- Chomsky, N. 1986b. Barriers, MIT Press, Cambridge, Mass.
- Lasnik, H. and M. Saito 1984. On the nature of proper government, Linguistic Inquiry 15, pp. 235-289