the A, B, C & W prefixes refer to the relative sensitivity of the range of rotation for the pot. an Alpha taper (prefix A) gives you more control during the first third of its rotation. Usually used for volume controls based on the idea that our hearing is more sensitive to quiet sounds compared to loud sounds. Linear pots (prefix B) have their resistance evenly distributed over their rotation. They work better for things like setting a rate for an effect, like tremolo or repeats on a delay. You can do a google search to learn more about these tapers, along the reverse tapers (sensitivity at the end of the rotation) and the hybrid taper that has opposite sesitivities at each end of the rotation.
So if you swap a B100k pot for a C100k pot it will work, but the "feel" of the pot during that rotation will be a bit different. In practice you can sub these parts for your own pedals and it probably will not bother you enough to go back and change it when you get the right part. But you would be less likely to sub the part if you were building it for a friend or a customer.
