as well, the suffixes are combined. 6. In H and O layers, the i, e or a is written first. 7. The @, f and b are written last, if b occurs together with @ or f (only if other suffixes are present as well): @b, fb. 8. Besides that, combinations must be in the sequence of dominance, the dominant one first. Examples: Btng, Btgb, Bkcyc. Transitional layers If the characteristics of two or more master layers are superimposed to each other, the master symbols are combined without anything in between, the dominant one first, each one followed by its suffixes. Examples: AhBw, BwAh, AhE, EAh, EBg, BgE, BwC, CBw, BsC, CBs. If the characteristics of two or more master layers occur in the same depth range, but occupy distinct parts clearly separated from each other, the master symbols are combined with the slash (/), the dominant one first, each one followed by its suffixes. Examples: Bt/E (interfingering of E material into a Bt horizon), C/Bt (Bt horizon forming lamellae within a C layer). W cannot be combined with other master symbols. H, O, I, and R can only be combined using the slash. Layer sequences The sequence of the layers is from top to down with a hyphen in between. If lithic discontinuities occur, the strata are indicated by preceding figures, starting with the second stratum. I and W layers are not considered as strata. All layers of the respective stratum are indicated by the figure: Example: Oi-Oe-Ah-E-2Bt-2C-3R. If two or more layers with the same designation occur, the letters are followed by figures. The sequence of figures continues across different strata. Examples: Oi-Oe-Oa-Ah-Bw1-Bw2-2Bw3-3Ahb1-3Eb-3Btb-4Ahb2-4C, Oi-He-Ha-Cr1-2Heb-2Hab-2Cr2-3Crγ. Diagnostic soil horizons Many soil classification systems have diagnostic horizons. A diagnostic horizon is a horizon used to define soil taxonomic units (e.g. to define soil types). The presence or absence of one or more diagnostic horizons in a required depth is used for the definition of a taxonomic unit. In addition, most classification systems use some other soil characteristics for the definition of taxonomic units. The diagnostic horizons need to be thoroughly defined by a set of criteria. When allocating a soil (a pedon, a soil profile) to a taxonomic unit, one has to check every horizon of this soil and decide, whether or not the horizon fulfils the criteria of a diagnostic horizon. Based on the identified diagnostic horizons, one can proceed