A new method to identify all sufficiently long repeating substrings in one or several symbol sequences is proposed. The method is based on a specific gauge applied to symbol sequences that guarantees identification of the repeating substrings. It allows the matching of substrings to contain a given level of errors. The gauge is based on the development of a heavily sparse dictionary of repeats, thus drastically accelerating the search procedure. Some genomic applications illustrate the method. This paper is the extended and detailed version of the presentation at the third International Conference on Algorithms for Computational Biology to be held at Trujillo, Spain, June 21-22, 2016.