For each element encountered in the source document, the MDF file must contain instructions on how to treat this element when generating the DTB fileset. These instructions are:
If Include in NCC is checked for the current element, this means that the current element should be included in the NCC document.
Include in NCC should be enabled only for the following elements:
If Linkback is checked for the current element, this means that the element in the content document will contain a link into the SMIL file. In this way, any element (such as paragraphs, sentences, words) can be activated in the DAISY DTB by clicking on them in the text display window. This is what is reffered to as "local navigation"
It is recommended to use linkback for all elements that have text synchronized with audio. This gives a very high quality DTB.
It also recommended that when linkback is enabled, a stylesheet (CSS) should be associated with the book. This stylesheet should remove the default blue underlined text style of the link.
The nested checkbox should be checked if the current element is a child of another element that also has text, and if the child element should become a synchronization item of its own.
Example:
<p>We strongly <em>emphasize</em> one word in this paragraph</p>
If <em> is included in the MDF with nested checked, the word "emphasize" in the example above will become a separate synchronization item inside the paragraph.
If <em> is included in the MDF with nested unchecked, the word "emphasize" in the example above will become a separate synchronization item apart from the paragraph. This should be avoided and should not be used.
If instead <em> is deleted from the MDF, the whole paragraph will be one synchronization item.
Level based on should be set to "nothing" except for headings, where "level based on" should have same value as heading depth.
Example:
Current element is "<h2>" - "level based on" should be "2"