GLOSSARY
- alternate description: An alternate description is text in a human-readable form, typically used by applications such as those running a text-to-speech engine or providing accessibility to persons with disabilities.
- annotation rectangle: An annotation rectangle is a rectangular area on a page where the given annotation is located.
- annotation handler: An annotation handler is a software module used to govern the behavior of an annotation type. A PDF viewer application has annotation handlers for all standard annotation types. For additional annotation types, handlers can be provided as plug-in extensions.
- appearance stream: An appearance stream is a form XObject representing a self-contained content stream that can be used to render an annotation inside an annotation rectangle, usually as an alternative to the simple border and color conventions used prior to PDF 1.2.
- bounding box: A bounding box is the smallest rectangle that can fit all contents of a given form XObject.
- dash pattern: A dash pattern is series of dashes and gaps representing a path. It is specified in terms of the lengths of the dashes and gaps, and distance (phase) into the pattern where the dash is started.
- destination: A destination is a particular view on a given document. The view is determined by:
- page to be displayed
- location of the window on the page
- zoom applied when displaying the page
- form XObject: A form XObject is a PDF content stream representing a self-contained description of a sequence of graphic objects, typically used to economically limit the size of the PDF file and to aid caching of such reusable objects in PDF applications.
- go-to action: A go-to action makes the viewer application to change the current view to a specified destination.
- Javascript action: A Javascript action makes the viewer application to compile and execute a Javascript script. Javascript actions are typically used to update various properties of form fields.
- launch action: A launch action makes the viewer application to execute an application or open/print a file with the file's default application. Launch actions are currently supported by Adobe only on Microsoft Windows platform.
- markup annotation: A markup annotation is any annotation whose type specifies text to mark up PDF documents. For example, sound annotations are markup annotations while watermark annotations are not. The text used to mark up PDF documents is useful when extracting the document's contents for applications such as those providing accessibility to persons with disabilities.
- named action: A named action is a designated action supported by a viewer application. In PDF 1.6, the following named actions have been designated:
- navigating to next page
- navigating to previous page
- navigating to first page
- navigating to last page
All PDF viewer applications are expected to support these named actions. Individual viewer applications may support named actions other than those specfied in PDF 1.6 but they are considered as non-standard named actions i.e., unless and until Adobe includes them in a future PDF version.
- path: A path is a line or a boundary of a shape, trajectory, or region. A path is made up of subpaths consisting of straight or curved line segments.
- remote go-to action: A remote go-to action makes the viewer application to display a specified destination in another document.
- URI action: A URI action makes the viewer application to resolve a uniform resource identifier (URI).