Reed-Solomon (RS) coding and interleaving are usually combined to protect Digital Subscriber Line (DSL) systems against Impulse Noise (IN) but introducing a long delay. It is proved that interleaving delay can be significantly reduced by Error and Erasure Decoding (EED). This paper proposes an erasure marking technique to enhance the reliability of the erasure information in order to completely exploit the capability of EED for interleaving delay reduction. Selection of proper parameters for the proposed erasure marking technique is analyzed. Simulation results show that the proposed technique can guarantee efficient erasure marking and reduce the interleaving delay by a factor of two.