Activity Streams is an open format specification for activity stream protocols, which are used to syndicate activities taken in social web applications and services, similar to those in Facebook's, Instagram's, and Twitter's. The standard provides a general way to represent activities.

Prefix
ac
Preferred Prefix
ac
Keywords
semantic web social media
Links
Homepage
Contact
Missing Contact
Pattern for Local Unique Identifiers
Missing LUI pattern
Example Local Unique Identifier
Add   Resolve
Example CURIE
ac:Add
Contributors
Ontology

A summary of the relations in the Bioregistry schema can be found here.

In Collection
Semantic Web Context
Providers

A provider turns a local unique identifiers from a resource into a URI. Many providers are also resolvable as URLs (i.e., they can be used in a web browser).

The local unique identifier Add is used to demonstrate the providers available for Activity Streams. A guide for curating additional providers can be found here.

Name Metaprefix URI
Activity Streams ac http://www.w3.org/ns/activitystreams#Add
Bioregistry bioregistry https://bioregistry.io/ac:Add