Hi,
Imagine A1 Website Download encounters a website with these 3 urls:
page?var=valueA
page?var=valueB
pagevar=valueA
When saving these to disk, e.g. "?" is not allowed in file names by Windows.
This would force A1WD do convert those URLs. End result file names on disk could be like this:
page?var=valueA :: pagevar=valueA
page?var=valueB ::pagevar=valueB
pagevar=valueA :: pagevar=valueA
But that gave collision... Above is just an example. There are many possible ways s collision can happen. And for various reasons the fastest/easiest/practical way to deal with that is to use the MS_xxx system (where xxx is a counter)
The MS_xxx system is only used when collisions are possible. Possibly the system can be improved upon, but collisions actually happen quite often (I tried various methods in past "modifying" URLs when saving to disk, but it often led to collisions. However, one could add separate tracking of this and only use MS_xxx when *really* necessary.)