# 6. XHTML Attribute Collections

Contents

This section is normative.

Many of the modules in this document define the required attributes for their elements. The elements in those modules may also reference zero or more attribute collections. Attribute collections are defined in their own modules, but the meta collection "Common" is defined in this section. The table below summarizes the attribute collections available.

Collection | Module | Description
--- | --- | ---
Core | Core Attributes Module | Basic attributes used to identify and classify elements and their content.
I18N | Internationalization Attribute Module | Attribute to identify the language of an element and its contents.
Bi-directional | Bi-directional Text Collection | Attributes used to manage bi-directional text.
Edit | Edit Attributes Module | Attributes used to annotate when and how an element's content was edited.
Embedding | Embedding Attributes Module | Attributes used to embed content from other resources within the current element.
Events | XML Events Module | Attributes that allow associating of events and event processing with an element and its contents.
Forms | XForms Module | Attributes that designate provide a mechanism of repeating table rows within a form.
Hypertext | Hyptertext Attributes Module | Attributes that designate characteristics of links within and among documents.
Map | Image Map Attributes Module | Attributes for defining and referencing client-side image maps.
Media | Media Attribute Module | Attribute for performing element selection based upon media type as defined in MediaDesc
Metainformation | Metainformation Attributes | Attributes that allow associating of elements with metainformation about those elements
Role | Role Attribute Module | Attribute for the specification of the "role" of an element.
Style | Style Attribute Module | Attribute for associating style information with an element and its contents.
Common | Attribute Collections Module | A meta-collection of all the other collections, including the Core, Bi-directional, Events, Edit, Embedding, Forms, Hypertext, I18N, Map, Media, Metainformation, Role, and Style attribute collections.

Implementation: RELAX NG

Each of the attributes defined in an XHTML attribute collection is available when its corresponding module is included in an XHTML Host Language or an XHTML Integration Set (see [XHTMLMOD]). In such a situation, the attributes are available for use on elements that are NOT in the XHTML namespace when they are referenced using their namespace-qualified identifier (e.g., `xhtml:id`). The semantics of the attributes remain the same regardless of whether they are referenced using their qualified identifier or not. If both the qualified and non-qualified identifier for an attribute are used on the same XHTML namespace element, the behavior is unspecified.

## 6.1. Issues

xml:id PR #7442
State: Suspended
Resolution: Defer
User: None

Notes:
If xml:id becomes stable document in time for use in this document, we will migrate to its use.

[XHTML2] Constraining attribute relationship PR #7661
State: Suspended
Resolution: Defer
User: None

Notes: