If I understand your question correctly you're asking if there's a way to link (for instance from a website) to a location within a publication? If you wish to link to a specific part of a EPUB, you can use EPUB Canonical Fragment Identifiers (epubcfi for short). The specification is available from here. EPUB Canonical Fragment Identifier (epubcfi) Specification I'm not familiar with it enough to say whether or not it will work with EPUB2 publications. But it will at least work with EPUB3 publications. Reading system support for epubcfis are not too good yet either, but it's coming; try this link and select "Content Fragment Identifiers" to check for epubcfi support. EPUBTest.. Compare I have not heard of any standard available for linking into MOBI files. As for PDFs, you might be able to link to parts of a PDF, but it probably depends on how well your PDF is marked up as well as what PDF reader you are using. Link HTML to PDF page | Pdf Converting 7, Pdf Converting 3D
Links in e-books Many of us use Kindle or iBooks apps, that display e-book files (with or without metadata) on the screen.