Where it comes from
The line in the source
"productTitle": "拡張パック「ダークラッシュ」", "releaseDate": "2011年12月16日（金）", "description": "カード／5枚" Explore / Figure
Record
JP expansion-pack release date, 16 December 2011 | 2011 | year to February 2012 (Mar 2011-Feb 2012) | print-year Apr 2011-Mar 2012
16 December 2011 16 December 2011 | 2011 | year to February 2012 (Mar 2011-Feb 2012) | print-year Apr 2011-Mar 2012
FiledTaken from a filing, a registry or the company’s own published page.
Found in one pass only. The research team reads every source twice, independently; this record turned up in one reading but not the other, so treat it as less certain than its grade.