| kf8 | Amazon Kindle Format 8 Ebook Metadata |
| kfx | Kindle v10 KFX Ebook |
| kfx-zip | Compressed Kindle KFX Ebook |
| koob | Koober E-Book |
| lit | Microsoft Reader E-Book Document |
| lmb | LenMus eBook |
| lrf | Sony BBeB E-Book |
| lrs | Sony BBeB E-Book Source |
| lrx | Sony BBeB E-Book |
| mart | MartView eBook |
| mbp1 | Amazon Kindle Touch Annotations Data |
| mbpkg | Mobipocket Reader Package |
| mbpv2 | Amazon Kindle Annotations Data |
| mobi | Mobipocket Reader E-Book |
| mpub | Mobcast Mobile Optimized ePub Book |
| nat | Natata eBook Compiler Document |
| ncx | EPUB Navigation Control XML |
| nh | China Academic Journals NH Document |
| nva | NVA eBook Document |
| oeb | Open Electronic Package Ebook |
| oebzip | Zipped Open eBook |
| opf | Open Electronic Package Ebook |
| pdb | Plucker Ebook |
| pdg | SSReader Digital Book |
| phl | Amazon Kindle Public Highlights Data |
| pkg | Apple Newton eBook |
| pml | Palm Markup Language File |
| pmlz | Compressed Palm Markup Language File |
| pobi | Kindle Touch Periodical Data |
| prc | Mobipocket Reader E-Book |