Awesome and flexible, these visas are only available to people aged 18-30 (or up to 35 in some nation) and in principle, you are only permitted to apply once per country.
這麼好康且極富彈性的簽證，僅有一項限制，就是只限 18 歲至 30 歲青年申請（部分國家開放至 35 歲），且原則上同一個國家每人僅能申請一次。