Notation	Name	Description	Status
0	Observing rules for base of lowest cloud and cloud types of FM 12 SYNOP and FM 13 SHIP apply		stable
1	First non-Cumulonimbus significant layer		stable
2	Second non-Cumulonimbus significant layer		stable
3	Third non-Cumulonimbus significant layer		stable
4	Cumulonimbus layer		stable
5	Ceiling		stable
6	Clouds not detected below the following height(s)		stable
7	Low cloud		stable
8	Middle cloud		stable
9	High cloud		stable
10	Cloud layer with base below and top above the station		stable
11	Cloud layer with base and top below the station level		stable
20	No clouds detected by the cloud detection system		stable
21	First instrument detected cloud layer		stable
22	Second instrument detected cloud layer		stable
23	Third instrument detected cloud layer		stable
24	Fourth instrument detected cloud layer		stable
62	Value not applicable		stable
63	Missing value		stable