I hope this helps..
From the MR Wiki....
https://wiki.mobileread.com/wiki/JetBook
# The ECTACO jetBook e-Book Reader supports TXT, PDF, FB2, ePUB, MOBI/PRC, RTF file formats
# DRM formats: None
In my understanding... If a file must use Adobe Digital Editions (ADE) then the file has DRM [members please comment if this is not correct]
If a format says secured then it has DRM.
So for the jetbook...
Sony Store ebooks (lrx)..... NO
Harlequin ebooks use ADE..... NO
[give-away page..... YES
but the freebies use ADE..... NO
Any ADE ePub or ADE pdf ..... NO
***There are ways around this but it requires some tech knowledge and scrips that MR doesn't give instructions for or links to***
