Why Sub Folder for Hyper linked reports in SAP Business Objects

Dear Experts,

We are using SAP Business Objects 3.1, in my organization we already have reports builded for different requirements. Every report has hyperlink with another report. Developer had created separate folder for all these hyperlinked reports.Now, my question is, why he might have created separate folder for these hyperlink reports.

Ex:

Folder1

subfolder

{ report4

report5

report6}

report1

report2

report3

report4

report5

report6

report7

report8

Can you please help me to understand why he had created sub folder for the existing reports.

Thanks,

Kote