B

• Biological classification (9 C, 52 P)

C

• Chemical classification (4 C, 5 P)

M

• Mathematical classification systems (10 P)
• Morphology (6 C, 9 P)

S

• Soil classification (1 C, 7 P)

T

• Taxonomy classification (1 C, 1 P)

• Scientific classification

C

• Classification of the sciences (Peirce)

D

• Division (taxonomy)
• Dustbin category

E

• Classification of electromagnetic fields

F

• Fields of Science and Technology

I

• IEC Common Data Dictionary

N

• Nickel–Strunz classification

P

• PhySH
• Physics and Astronomy Classification Scheme