Exchange comission and charges - A genuine question

they're charges you would have paid   ,except you got an allowance before pc kicked in .

So it includes them in the tally of "Total Charges" but I didn't actually pay them? How confusing.

Data charges

At the end of every day, we add up the total number of API and website data requests you made in each second and if you made more than 20 data requests in one second we charge you 0.1p per data request above 20.

It's the amount of PC you would have paid on the lifetime profit of your account before PC1 was introduced. Rather than backdating those charges BF very graciously decided to assume you had already paid them. It's separate from the initial allowance when you first reach PC.