ArcView specifies the 'm' and 'u' probabilities for each field of each address style in the .mat files located in the installation geocode directory.
These files are:
us_addr1.mat - used in US Streets with Zone address style.
us_addr2.mat - used in US Streets address style.
us_intsc.mat - used in both US Streets with Zone and US Streets
key_1.mat - used in Single Field address style.
zip4.mat - used in Zip+4 address style.