Cascading of attributes from map to map

Certain attributes cascade from map to map.

The following attributes cascade from map to map:

@rev
@props and any attribute specialized from @props, including those integrated by default in the OASIS-provided document-type shells: @audience, @deliveryTarget, @platform, @product, @otherprops
@linking, @toc, @search
@type
@translate
@processing-role
@cascade
@subjectrefs

As with values that cascade within a map, the cascading is additive if the attribute permits multiple values, such as @audience. For attributes that take a single value, the value that is defined on the closest containing element takes effect.

The following attributes do not cascade from map to map

@format: The @format attribute is set to ditamap when a map or map branch is referenced, so it cannot cascade through to the referenced map.
@scope: The value of the @scope attribute describes the map itself, rather than the content. For example, when the @scope attribute is set to external, it indicates that the referenced map itself is external and unavailable, so the value cannot cascade into that referenced map.
@xml:lang and @dir: Cascading behavior for @xml:lang is defined in The xml:lang attribute. The @dir attribute follows the same rules as @xml:lang.

While the @class attribute is unique and does not cascade, the value of the attribute is used to determine the processing roles that cascade from map to map. See Cascading of roles from map to map for more information.