The Short Version
Informal ability-based labeling by teachers does occur in Indonesian classrooms, but the claim misrepresents this as an official "standard practice" of the national education system. Indonesia's current national framework — Kurikulum Merdeka, implemented since 2022 — explicitly promotes inclusive, differentiated learning and has eliminated discriminatory tracking such as high school subject-stream majors. The most authoritative sources (OECD, Indonesian Ministry of Education) describe national policy as moving in the opposite direction of what the claim implies.