A pipe-delimited ('|') list of values. Each value consists of a territory list of ISO 3166 two-letter country codes and a date, seperated by a colon (:). Use 'WW' as a code for a worldwide start date. You can exclude territories from a worldwide start date by prepending a '-' sign in front of their country codes. To remove availability from an existing track, leave this column empty. Example 1: 'CA:2013-03-30|US,JP:2013-03-30' specifies one start date for Canada and one for the US and Japan. Example 2: 'WW-US-JP: 2013-03-30|US JP:2013-01-30' specifies a start date that applies everywhere except the US and Japan, which has an earlier start date.