PDF Output

Predefined Meta Fields

Suppose that you have the following arbitrary XML document:

<doc>
     <title>Publication title</title>
     <meta name='keywords' content='software, network'>
     <meta name='description' content='This is a publication about software products...'>
     <meta name='author' content='John, jo@mysite.example.com'>
     <meta name='copyright' content='Copyright My Company 2021'>

...

You could use any of the following CSS selectors to extract the metadata:

Custom Meta Fields

Metadata is not restricted to the above cases. You may have custom metadata fields. It is usually displayed in a tabular format (for example, in Acrobat Reader ™, it is in the Custom tab in the Properties dialog box).

PDF Accessibility Tagging

By default, Oxygen PDF Chemistry partially creates accessible PDF documents in the sense that most of the paragraphs, tables, lists, headers, and footers are tagged automatically for any XML vocabulary, and PDF readers use this information to present the content.

In addition, the default CSS files used by Oxygen PDF Chemistry to generate PDF based on HTML defines accessibility tags for headings (H1..H6), quotations (Q), sections (SECTION), and pre-formatted text (PRE).

However, this tagging just takes the element name into account. If your element has a different semantic, you can impose a different PDF accessibility tag by using the -oxy-pdf-tag-type extension. In the following example, a paragraph with the note class will be marked:

p.note {
  -oxy-pdf-tag-type: "Note";
}

Hints for Making Documents More Accessible

Fully Accessible PDF (PDF/UA1)

To make the PDF fully accessible, you have to activate the PDF/UA-1 mode. PDF/UA documents meet the regulations set in Section 508. This mode has special requirements:

1. Activate the PDF UA-1 mode from the command line using the -pdf-ua parameter.
2. All the fonts must be embedded. If you are using one of the basic fonts (such as "Times", "Helvetica", etc.), make sure you explicitly define CSS font faces for them. For details, see: Font Embedding.
   Troubleshooting: If you are using fonts other than the basic ones and still have problems embedding the basic default fonts, make sure all elements are styled using one of your fonts of choice. A catch all CSS rule might be helpful:

   :root{
     font-family: Arial;
   }
   
   @page {
       @top-left {font-family: Arial }
       @top-right {font-family: Arial }
       @top-center {font-family: Arial }
       @top-left-corner {font-family: Arial }
       @top-right-corner {font-family: Arial }
       
       @bottom-left {font-family: Arial }
       @bottom-right {font-family: Arial }
       @bottom-center {font-family: Arial }
       @bottom-left-corner {font-family: Arial }
       @bottom-right-corner {font-family: Arial }
   }

3. The title of the document must be marked using the metadata. This is important for accessibility since it will allow the screen reader to identify the publication title. This is important for accessibility since it will allow the screen reader to identify the publication title. This is an example using the -oxy-pdf-meta-title extension:

   title {
       -oxy-pdf-meta-title: content(text);
   }

   Note: The default CSS files for generating PDF based on HTML already contains this rule.

Tools for Checking the Document Accessibility

• For smaller documents, this site might be helpful: http://www.access-for-all.ch/ch/pdf-werkstatt/pdf-accessibility-checker-pac.html
• From Adobe: https://helpx.adobe.com/acrobat/using/create-verify-pdf-accessibility.html