tick-mark label (n)~ A label that identifies the categories values or series in a chart. TID (n)~ A 9-digit number used to identify an entity (company or person) for tax reporting purposes in the U.S. There are several different types of tax identification numbers such as employer identification number (EIN) Social Security number (SSN) individual taxpayer identification number (ITIN) and adopted taxpayer identification number (ATIN).