Methods, apparatuses (e.g., DSL system hardware, DSL systems, vectoring control entities), techniques, systems, etc. are used for initializing one or more DSL lines joining a vectored DSL line group operating in Showtime. A super-periodic orthogonal pilot sequence from a set of super-periodic orthogonal pilot sequences is assigned to each joining DSL line, wherein each such super-periodic orthogonal pilot sequence in the set has length L and is orthogonal to other sequences in the set over length T. These super-periodic orthogonal pilot sequences are used on the joining DSL lines to generate at least T sync-symbols worth of initialization data, which is processed to generate initialization data and FEXT mitigation coefficients for use when the joining DSL lines become part of the vectored DSL line group.