[Figure 1] Investigative procedures Case accepted 2024.1.23 Investigation approved 2024.2.22 Data collection / Issuance of official letters to government agencies Interview with the TFAU 2024.2.29 Consultation with government agencies 2024.5.30 Interviews with cabin crew and airlines 2024.3.22 2024.5.16 Consultation with scholars and NGOs 2024.3.15 Writing of interview outlines Investigative report advisory meeting 2024.7.6 Investigation results submmited for approval 2024.7.23 [Data sources] The NHRC 1) Data collection and issuance of official letters of inquiry to government agencies In addition to the documentation provided by the complainant, the NHRC collected evidence from a wide range of sources and issued official letters to government agencies to request additional data, including airline company bylaws, official government approval documents, meeting minutes, investigative reports, and domestic and international dress code studies. 2) Interviews with stakeholders The NHRC interviewed union members, cabin crew, and airline representatives. It is worth noting that, despite the NHRC’s plans to interview cabin crew from all six airlines, only cabin crew from two of the airlines agreed to take part in the investigation (representatives of all six airlines participated in interviews). Prior to the start of each interview, the participants were informed of the NHRC’s authority and the purpose of the interview. 14