W3C Standards

Web Annotation Data Model

Annotations are typically used to convey information about a resource or associations between resources. Simple examples include a comment or tag on a single web page or image, or a blog post about a news article.

The Web Annotation Data Model specification describes a structured model and format to enable annotations to be shared and reused across different hardware and software platforms. Common use cases can be modeled in a manner that is simple and convenient, while at the same time enabling more complex requirements, including linking arbitrary content to a particular data point or to segments of timed multimedia resources.

For example:

• Adding a Comment to a Web Page
• Tagging an Image
• Linking a Specific Time Segment in a Video

The specification provides a specific JSON format for ease of creation and consumption of annotations based on the conceptual model that accommodates these use cases, and the vocabulary of terms that represents it.

Activity Streams 2.0

This specification details a model for representing potential and completed activities using the JSON format. It is intended to be used with vocabularies that detail the structure of activities, and define specific types of activities.

For example:

• Liking a Post
• Sharing an Article
• Completing a Task

Web Content Accessibility Guidelines (WCAG) 2.2

Web Content Accessibility Guidelines (WCAG) 2.2 covers a wide range of recommendations for making Web content more accessible. Following these guidelines will make content more accessible to a wider range of people with disabilities, including accommodations for blindness and low vision, deafness and hearing loss, limited movement, speech disabilities, photosensitivity, and combinations of these, and some accommodation for learning disabilities and cognitive limitations; but will not address every user need for people with these disabilities. These guidelines address accessibility of web content on desktops, laptops, tablets, and mobile devices. Following these guidelines will also often make Web content more usable to users in general.

For example:

• Providing Text Alternatives for Images
• Ensuring Keyboard Navigation
• High Contrast for Text Readability

References

• https://www.w3.org/TR/annotation-model/
• https://www.w3.org/TR/activitystreams-core/
• https://www.w3.org/TR/WCAG22/