### Must support
The meaning of the presence or absence of the must support flag is described in [Must support](guidance.html#must-support).

### Extensions
No extensions have been introduced in this profile.

### Usage notes
When [updating an existing task resource](CapabilityStatement-pca-subscriber-agent.html#update), *note* can only be updated if *status* is being changed from 'completed' to 'failed'.

### Supported interactions
Supported service interactions for this profile are defined in the following capability statements:
* For publishing systems: [PCA Publisher Agent](CapabilityStatement-pca-publisher-agent.html#task)
* For subscribing systems: [PCA Subscriber Agent](CapabilityStatement-pca-subscriber-agent.html#task)
 