The Hong Kong Christian Service website says that in Hong Kong "hidden youth" are defined as those who have not been in contact with or participated in "external systems" for three months. These external systems include social networks such as work, school, friends or community. In more serious cases, such youth lack even contact with internal networks (i.e. their families).
根據香港基督教服務處網站的資料顯示，香港對「隱蔽青年」的定義，就是持續 3 個月缺乏與外在系統的聯繫或參與，包括工作、學校、朋友、社區等，更嚴重者，甚至連和內在系統（即家庭系統）也缺乏連繫。