What is haunting adeline pdf?

Unfortunately, as an AI Language model, I do not have the ability to access external information and sources. However, I can provide you with some general information about the concept of PDFs.

PDF refers to Portable Document Format, which is a file format used to present and exchange documents reliably, independent of hardware, software, or operating system. PDFs look the same on any device and can be easily shared across different platforms.

Haunting Adeline may refer to a book or a document that is in PDF format. Without further context, it is difficult to provide more information.