Setting parameters for custom HTML 
  
  For simple branded HTML pages, you can adjust the look and feel of the default output to match your company
    style by setting parameters to include custom CSS, header branding, or table-of-contents navigation in topics.
    (These changes do not require a custom plug-in.)
  
Adding navigation to topics  In HTML5 output, you can set a parameter to include table-of-contents navigation in the       <nav> element of each page. The navigation can be rendered in a sidebar or menu via     CSS.Adding custom CSS  To modify the appearance of the default HTML output that DITA Open Toolkit generates, you can reference a     custom Cascading Style Sheet (CSS) file with the typography, colors, and other presentation aspects that define your     corporate identity.Adding custom headers and footers  You add a custom header to include a publication title, company logo, or other common branding elements in     HTML output. A custom footer can also be added with copyright information, legal boilerplate, or other fine     print.Handling content outside the map directory  By default, DITA-OT assumes content is located in or beneath the directory containing the DITA map file.     The generate.copy.outer  parameter can be used to adjust how output is generated for content     that is located outside the map directory.