In one example in accordance with the present disclosure, a method may include receiving a digit sequence including a subset of N digits encoded with semantic information and determining a set of possible combinations for the N digits in the subset. The method may also include establishing a mapping between each possible combination in the set of possible combinations and a corresponding integer sequence belonging to a set of integer sequences. Each integer sequence in the set of integer sequences is of the length of N−1. The method may also include identifying a selected integer sequence corresponding to the subset and replacing n−1 digits from the subset with the selected integer sequence. The method may also include replacing a digit of the subset with a digit value calculated to produce a valid checksum for the entire first digit sequence, wherein the first digit is not included in the n−1 digits.