Allow configuration to provide access to each piece of unrendered conditional content "C".
When a specification does not explain how to provide access to this content, do so as follows:
If C is a summary, title, alternative, description, or expansion of another piece of content D, provide access through at least one of the following mechanisms:
(1a) render C in place of D;
(2a) render C in addition to D;
(3a) provide access to C by allowing the user to query D. In this case, the user agent must also alert the user, on a per-element basis, to the existence of C (so that the user knows to query D); and
(4a) allow the user to follow a link to C from the context of D.
Otherwise, provide access to C through at least one of the following mechanisms:
(1b) render a placeholder for C, and allow the user to view the original author-supplied content associated with each placeholder;
(2b) provide access to C by query (e.g., allow the user to query an element for its attributes). In this case, the user agent must also alert the user, on a per-element basis, to the existence of C; and
(3b) allow the user to follow a link in context to C.
Sufficient techniques
To satisfy provision one of this checkpoint, the configuration may be a switch that, for all content, turns on or off the access mechanisms described in provision two.
To satisfy provision two of this checkpoint, the user agent may provide access on a per-element basis (e.g., by allowing the user to query individual elements) or for all elements (e.g., by offering a configuration to render conditional content all the time).
To satisfy the requirement of provision two of this checkpoint to allow the user to view the content associated with each placeholder, the user agent may either render the associated content in a separate viewport or in place of the placeholder.
Normative inclusions and exclusions
For the placeholder requirement of provision two of this checkpoint, a request to view the original content associated with a placeholder is considered an explicit user request to render that content.
The user agent is not required to include placeholders in the document object. A placeholder that is part of the document object should conform to the Web Content Accessibility Guidelines 1.0 [WCAG10]. If a placeholder is not part of the document object, it is part of the user interface only (and subject, for example, to checkpoint 1.3).