If you want to transmit your Xaddress by phone you will say
"7150 MAGICAL PEARL - Maluku ,Indonesia" my avatar is a boot
By analogy, ECC memory can typically detect two bit errors but can only correct single bit errors. That's because the functionality used to detect two bit errors in ECC memory is insufficient to recover both bits.
Keeping a minimal edit distance between code words in the corpus would enable error detection and correction without the burden of sending another piece of info.