Canada changes to Net Claim Amount on Paycheques

I'm reading the documentation on the changes to Net Claim Amount on Paycheques for Canada and had a question about what exactly is the 'calculated net claim amount'? The only definition I can find in the document states : 'Net Claim Calculated – the basic net claim amount when applying the BPAF formula.'

This isn't really, clear, and I'm wondering if the 'calculated net claim amount' is an amount that the pay-calc program is deriving based on the CIT Taxable Gross on the employee's paycheque? Any insight is greatly appreciated.