A bag specified by authorities (often refers to designated garbage bags); commonly used interchangeably with 'designated garbage bag' depending on context.
この地区では指定袋以外のゴミは収集されない。
In this area, garbage in bags other than the designated ones will not be collected.
指定袋のデザインが自治体ごとに違う。
The design of the designated bags differs by municipality.
スーパーで指定袋を買って、分別して出してください。
Buy the designated bags at the supermarket and sort your waste before putting it out.