A-scale pots are "audio" scale, which is sort-of logarithmic. That's your 100k pot.
B-scale pots are linear, i.e. uniform track width. That's your 10k pot.
See this reference on potsreference on pots including markings.
The arrows on the schematic tell you which way they're physically oriented; I think the arrow indicates motion of the wiper with clockwise rotation but am not sure about that.