The Commission for Air Quality Management (CAQM) in Delhi-NCR has imposed the Stage-lV ('Severe+' Air Quality) actions of the updated Graded Response Action Plan (GRAP) in addition to the Stage-I, II, and III actions that are already in effect to combat the rising pollution crisis in the national capital. The national capital's air quality index (AQI) was 441 (Severe) around 4 p.m. on Sunday, according to CAQM. The AQI recorded 447, 452, and 457 at 5 p.m., 6 p.m., and 7 p.m. on Sunday, respectively, indicating that it has been steadily rising further and has now reached the Severe+ category.Delhi's air quality is categorized into four stages according to the National Capital Region's (NCR) Graded Response Action Plan (GRAP): Stage I is "poor" (AQI 201-300); Stage II is "very poor" (AQI 301-400); Stage III is "severe" (AQI 401-450); and Stage IV is "severe plus" (AQI >450). An eight-point action plan aimed at reducing the pollution situation is part of the Stage-IV response. The prohibition of non-essential truck traffic entering Delhi, with the exception of vehicles transporting necessities or rendering necessary services, is one of the main measures.All students, with the exception of those in Classes 10 and 12, will no longer attend in-person classes as a result of the implementation of GRAP-4 tomorrow. Delhi CM Atishi tweets that all schools will offer online instruction until further notice.— ANI (@ANI) Grap 4 restriction: what's allowed and what's not1. Even for classes VI–IX and XI, the NCR State Governments and GNCTD may decide to stop holding in-person classes and instead teach online. 2. NCR State Governments/GNCTD will decide whether to permit 50% of employees in governmental, municipal, and private offices to work from home.3. GRAP Stage 4 entails ban on diesel-run medium, heavy goods vehicles registered in Delhi (BS-IV or below), except those carrying essentials.4. Entry of trucks into Delhi banned except for those carrying essential goods, services; LNG, CNG, electric, BS-VI diesel trucks allowed: CAQM.5. Prevent trucks from entering Delhi, unless they are transporting necessities or rendering necessary services. However, all trucks (LNG, CNG, electric, and BS-VI diesel) will be allowed entry into Delhi.6. Ban od C & D activities, as in GRAP Stage 3, also for linear public projects such as highways, roads, flyovers, overbridges, power transmission, pipelines, etc.7. State government may consider additional emergency measures like closure of colleges/educational institutions and closure of non-emergency commercial activities, permitting running of vehicles, and odd-even basis of registration numbers etc. 8. The Central Government has the authority to decide whether to allow its employees to work from home.In addition to the Stage I, Stage II, and Stage III citizen charters, citizens may be urged to follow the following guidelines and help ensure the successful implementation of the GRAP measures aimed at maintaining and improving the air quality in the region: Children, the elderly, and those with respiratory, cardiovascular, cerebrovascular, or other chronic diseases should stay indoors as much as possible and refrain from outdoor activities.