Illinois BP Lease Question

[Dan Shelhamer]

I use the Bigger Pocket's Residential Lease for my rental's.  However, I am a little confused with their verbiage on the late payment part.

"(E) Rent (including any Additional Rent) is due on the first (1st) day of each calendar month.Time of such payment is of the essence of this agreement. Any payments paid after the __fifth___ day of any calendar month shall be deemed late. Any late payments shall be charged a $_________ late fee for the first day rent is late. . The Rent shall be automatically increased $10, plus 5% of the amount by which the Rent exceeds $500, as additional rent, if received by Landlord after the 5th of the month for which it is due. All late fees shall be deemed Additional Rent payable by Tenant."

It seems very complicated.  The rent being increased by $10?  Does that mean every month going forward the rent is $10 more?  I use Buildium, and their doesn't seem to be a way to input this type of late charge.