Notation	Name	Description	Status
1	Surface		stable
2	Standard level		stable
3	Tropopause level		stable
4	Maximum wind level		stable
5	Significant temperature level		stable
6	Significant humidity level		stable
7	Significant wind level		stable
8	Beginning of missing temperature data		stable
9	End of missing temperature data		stable
10	Beginning of missing humidity data		stable
11	End of missing humidity data		stable
12	Beginning of missing wind data		stable
13	End of missing wind data		stable
14	Top of wind sounding		stable
15	Level determined by regional decision		stable
17	Pressure level originally indicated by height as the vertical coordinate		stable