Soil Moisture Regimes - Moisture Control Section

Moisture Control Section in Illustrated Guide to soil taxonomy 2014 is defined :
The upper boundary of the MCS is the depth to which a dry soil will be wetted by 2.5 cm of precipitation in a 24-hour period. The lower boundary is the depth to which the same soil will be wetted by 7.5 cm of precipitation in a 24-hour period. (page 1-10)

and

In Keys to soil Taxonomy 2014 defined:
The upper boundary of this control section is the depth to which a dry (tension of more than 1500 kPa, but not air-dry) soil will be moistened by 2.5 cm of water within 24 hours. The lower boundary is the depth to which a dry soil will be moistened by 7.5 cm of water within 48 hours. (page 29)