https://docs.podman.io/en/latest/markdown/podman-network-create.1.html#label-label

--label mykey=value

--label=com.example.demo-label=example-value

Label keys can contain lowercase alphanumeric characters, periods (.) and hyphens (-). They must start and end with an alphanumeric character. DNS notation rules are followed so multiple consecutive periods and hyphens are disallowed.

set container name c1 label vyos value 'my label'