The Portable Document Format (PDF) developed by Adobe can be made accessible, but it very much depends on how the original document is designed. If it is a poster created in a publishing application, scanned or saved from a Word document and locked down for copyright reasons then saved as PDF, it is liable to act in the same way as a picture. This means the text cannot be read by a screen reader or adapted for easier reading. It is appreciated that the concept of the PDF is to ensure that printed or saved versions of a document remain as the author intends, but there are ways to help the reader who uses assistive technologies or requires different formats of the text and graphics.