It has come to my attention that some spells have what could be considered charges. Take for example the spell
Burning Aura. It has a maximum of 240 charges before it dissipates. Field175 I believe refers to the type of spell being used, and only spells that have the numhits field populated have anything in field175. Burning Aura has a value of 1 in Field175, for example.
I looked and the values range between 1-9 (minus 4) and I've cross checked each of them with several spells in each value, but I couldn't link them to anything specific on the spell data from Allakhazam.
I thought it was liked to Category on Allakhazam, but I came across several anomalies that didn't seem to welcome that theory, however.