We propose advanced FEC (Forward Error Correction) codeword configurations and decoding strategies that are suitable for next-generation optical communication systems. They consist of the concatenation of a BCH-like binary code and an interleaved nonbinary code with iterative hard-decision decoding. The BER (Bit Error Rate) analysis results as low as 10/sub -15/ show that the proposed scheme outperforms the existing FEC schemes based on product codes. Our super-FEC scheme can be added to the existing ITU-FEC systems at low cost without much extra circuitry or much extra power consumption.