There is a command group 'az_acr_config_retention'. This group of commands could 'manage retention policy for azure container registries'. The group of commands has global parameter '--debug' which means 'Increase logging verbosity to show all debug logs.'. The group of commands has global parameter '--help -h' which means 'Show this help message and exit.'. The group of commands has global parameter '--only-show-errors' which means 'Only show errors, suppressing warnings.'. The group of commands has global parameter '--output -o' which means 'Output format.'. The group of commands has global parameter '--query' which means 'JMESPath query string. See <a href="http://jmespath.org/">http://jmespath.org/</a> for more information and examples.'. The group of commands has global parameter '--subscription' which means 'Name or ID of subscription. You can configure the default subscription using `az account set -s NAME_OR_ID`.'. The group of commands has global parameter '--verbose' which means 'Increase logging verbosity. Use --debug for full debug logs.'. This group contains a child command 'az_acr_config_retention_update'.The syntax is: az acr config retention update --registry
                               --type {untaggedmanifests}
                               [--days]
                               [--resource-group]
                               [--status {disabled, enabled}]. The 1th example of the child command would be to use it to 'enable retention policy for an azure container registry to delete an untagged manifest after 30 days', the syntax is: az acr config retention update -r myregistry --status Enabled --days 30 --type UntaggedManifests. The 2th example of the child command would be to use it to 'enable retention policy for an azure container registry to delete a manifest as soon as it gets untagged', the syntax is: az acr config retention update -r myregistry --status Enabled --days 0 --type UntaggedManifests. The parameter '--registry -r' is required. It is used to the name of the container registry. it should be specified in lower case. you can configure the default registry name using `az configure --defaults acr=<registry name>`.. The parameter '--type' is required. It is used to the type of retention policy.. The parameter '--days' is optional. the number of days to retain an untagged manifest after which it gets purged (range: 0 to 365). value "0" will delete untagged manifests immediately.. The parameter '--resource-group -g' is optional. name of resource group. you can configure the default group using `az configure --defaults group=<name>`.. The parameter '--status' is optional. indicates whether retention policy is enabled.. 