In the previous sections, we described how to construct address sequences that can serve as unique identifiers of the blocks they are associated with. We also pointed out that once such address sequences are identified, user information has to be encoded in order to avoid the appearance of any of the addresses, sufficiently long substrings of the addresses, or substrings similar to the addresses in the resulting DNA codeword blocks. For this purpose, we developed new prefix-synchronized encoding schemes based on ideas presented in14, but generalized to accommodate multiple sequence avoidance.