I tried it.
It checks for an article in a section being downloaded in the past.
It creates a file for each section.
so if article x is downloaded in section 1 it will not be downloaded into section 1 ever again.
However, if article x is in section 1, in this months mag, it can still be in section 2 in the same month. Same article in 2 sections.
My way means no article is repeated in any section within a single download.
(at least that's what happened for me) I hope that's the case cus that took me all morning (i'm not a programmer)