Core Viewpoint - The article discusses a recent incident involving a mother traveling with four children on a high-speed train, highlighting the confusion regarding ticket purchasing rules for children based on age [1]. Ticket Purchase Rules - Children tickets are now based on "age" rather than "height," as per the Railway Passenger Transport Regulations [2]. - Three categories for children's ticket purchases are outlined: - Children under 6 years old can travel for free if they do not occupy a separate seat, with one adult allowed to carry them for free [2]. - Children aged 6 to under 14 years must purchase a children's discount ticket [3]. - Children aged 14 years and older must purchase a full-price ticket, similar to adults [4]. Ticket Purchase Process - To purchase children's tickets or declare free travel for children, the 12306 App can be used for quick processing [6]. - Steps for declaring free travel for children under 6 include: 1. Purchase an adult ticket first [7]. 2. Navigate to the order section and declare the child's information [10]. - For purchasing children's discount tickets (ages 6-14), valid identification is required [13]. - Steps include: 1. Open the 12306 App and add the child's information under the passenger section [14]. 2. Select the train and complete the payment [18]. Documentation Requirements - For children with an ID card, a temporary ID can be obtained if lost [19]. - For children without an ID, a household registration book or passport is needed for entry [22]. - A list of valid identification documents for ticket purchases is provided, including various forms of ID and passports [23]. Travel Tips - During peak travel seasons, it is advised to arrive early and ensure all necessary documents are prepared [24].