If the first and second tier attempts both produce names longer than 25 characters, the naming scheme resorts to Tier 3 naming, using the literal “pattern” used when defining a Variant manually (i.e. using the Variant Definition Syntax described in section 1.3.2.5.2). These are patterns such as d(10-50), s(10,C), or m(10-50)s(51,C)m(52-80). The Variant Definition Syntax can be more compact than the Tier 2 naming scheme because it uses single letter abbreviations for the change types (m, d, i, s), as opposed to the 3-letter abbreviations seen above (REF, DEL, INS, SUB). Also, Tier 3 naming does not spell out the lengths of matches and deletions, and it concatenates haplotype codes without any separating characters like the comma used in Tier 2. However, these names are less convenient to sort through because they start with an abbreviated change type rather than a Reference position.