 The SRT database uses its own index-numbering system, while also preserving the "ITI" and "STWR" numbers when such designations already exist for a particular tartan.SRT users can register new tartans for a fee via the website or post, search for and request the thread counts of existing tartans (after registering for a free account), and receive notifications of newly registered tartans.The criteria for a new registration are fairly restrictive, requiring a clearly distinct name following one of several prescribed patterns, which must not confusingly misuse various pre-defined terms; authority to use the name, especially if it implies official recognition and acceptance by a clan, an organisation, or a jurisdiction; a design "sufficiently different" from all previously recorded tartans; and either a woven sample, a photograph thereof, or an accurate digitally rendered picture of the tartan.