The prefix pattern of the external annotation file. The prefix pattern followed by the filename of image being thumbnailed (with or without the extension) followed by the suffix pattern will form the external annotation filename.
Within the pattern one can specify a schema for multipage files to indicate page numbers: :$####: is the schema : indicates the start of the schema $ indicates the root, this can be whatever the user specfies, e.g., "MyPages" # indicates the page number or a placeholder : indicates the end of the schema For example, if the pattern string is "_ann.annotationfile.:pg####:" where the schema of the pattern is ":pg####:" The schema would be transformed to: "_ann.annotationfile.pg0001", "_ann.annotationfile.pg0002", "_ann.annotationfile.pg0003"