Prefix Mapping:

When the metadata properties Defined in this document are included in an EPUB 3 Package Document, they must be mapped to the URIhttp://www.idpf.org/vocab/rendition/# using the prefix attribute.

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Implementors should note that future revisions may establish the vocabulary represented by the URI http://www.idpf.org/vocab/rendition/# as a reserved vocabulary. In this case, the result will be that a) explicit mapping declaration using the prefix attribute will no longer be applicable, and b) the prefix ‘rendition’ will be reserved for this vocabulary. Future revisions of may also integrate the properties defined here into the Package Document default vocabulary. In this case the properties defined herein will be allowed to occur in Package Documents without a prefix.

Note that Package Documents may include additional proprietary metadata properties that pertain to layout expressions. Reading Systems must ignore such expressions if they conflict behaviorally with the Property semantics defined in this document.

Specifying name-value pairs on the spine itemref element:

In the context of the properties defined in this document, and when specifying property name-value pairs in the properties attribute on the Package Document spine itemref element, the following syntax must be used.

The property name and value is concatenated into a single string using a hyphen-minus character (U+002D) as separator. Note that leading and trailing whitespace around the separator character is not allowed.

For example, to express that the rendition:layout property has the value ‘reflowable’ for the given spine item, the string ‘rendition:layout-reflowable’ is used:

The rendition:layout property:

The rendition:layout property essentially tells a reading system whether the ePUB or spine element is reflowable or pre-paginated (fixed-layout). When using this property, there are literally these two choices: reflowable or pre-paginated. The default value is reflowable, so if the property is not defined in the metadata section or the spine, the ePUB content will render as reflowable text.

Using this property in the metadata would look like this:

reflowable

pre-paginated

If this property is used in the spine within an itemref, the property is defined immediately following the item id. In the spine, using this property would look like this:

The rendition:orientation property:

The rendition:orientation property specifies in which orientation the ePUB creator wants the publication or spine element to be rendered. There are three possible values for rendition:orientation: landscape, portrait, or auto. The default value for this property is auto or “the given spine item is not orientation constrained,” meaning the element should render according to device orientation or default.

In the metadata section, rendition:orientation would look like this:

auto

portrait

landscape

If this property is used in the spine within an itemref, the property is defined immediately following the item id. In the spine, using this property would look like this:

The rendition:spread property:

The rendition:spread property “specifies the intended Reading System synthetic spread behavior for this Publication or spine item” where synthetic spread is defined as the rendering of two adjacent pages simultaneously on the device screen. If you are working in the print environment, this would be the equivalent of having an image cut into two images that connects in the gutter across a two-page spread.

There are five possible values for rendition:spread: none, landscape, portrait, both, or auto. The value none means spreads should never be rendered; landscape means spreads should only be rendered when the device is in landscape orientation; portrait means spreads should only be rendered when the device is in portrait orientation; both means spreads should be rendered both when the device is in landscape orientation and when the device is in portrait orientation. The default value for this property is auto or “No explicit synthetic spread behavior is defined. Reading Systems may use synthetic spreads in specific or all device orientations as part of a display area utilization optimization process.” In other words, the Reading Systems will decide how to render the page.

In the metadata section, rendition:spread would look like this:

auto

none

landscape

portrait

both

If this property is used in the spine within an itemref, the property is defined immediately following the item id. In the spine, using this property would look like this: