Resource quotas appear in multiple APIs, OpenStackClient presents them as a single object with multiple properties.
Block Storage v1, Compute v2, Network v2
Set quotas for project
os quota set
    # Compute settings
    [--cores <num-cores>]
    [--fixed-ips <num-fixed-ips>]
    [--floating-ips <num-floating-ips>]
    [--injected-file-size <injected-file-bytes>]
    [--injected-files <num-injected-files>]
    [--instances <num-instances>]
    [--key-pairs <num-key-pairs>]
    [--properties <num-properties>]
    [--ram <ram-mb>]
    [--server-groups <num-server-groups>]
    [--server-group-members <num-server-group-members>]
    # Block Storage settings
    [--gigabytes <new-gigabytes>]
    [--snapshots <new-snapshots>]
    [--volumes <new-volumes>]
    [--volume-type <volume-type>]
    # Network settings
    [--floating-ips <num-floatingips>]
    [--secgroup-rules <num-security-group-rules>]
    [--secgroups <num-security-groups>]
    [--networks <num-networks>]
    [--subnets <num-subnets>]
    [--ports <num-ports>]
    [--routers <num-routers>]
    [--rbac-policies <num-rbac-policies>]
    [--vips <num-vips>]
    [--subnetpools <num-subnetpools>]
    [--members <num-members>]
    [--health-monitors <num-health-monitors>]
    <project>
Set quotas for class
os quota set
    --class
    # Compute settings
    [--cores <num-cores>]
    [--fixed-ips <num-fixed-ips>]
    [--floating-ips <num-floating-ips>]
    [--injected-file-size <injected-file-bytes>]
    [--injected-files <num-injected-files>]
    [--instances <num-instances>]
    [--key-pairs <num-key-pairs>]
    [--properties <num-properties>]
    [--ram <ram-mb>]
    [--server-groups <num-server-groups>]
    [--server-group-members <num-server-group-members>]
    # Block Storage settings
    [--gigabytes <new-gigabytes>]
    [--snapshots <new-snapshots>]
    [--volumes <new-volumes>]
    <class>
Set quotas for <class>
New value for the properties quota
New value for the ram quota
New value for the secgroup-rules quota
New value for the instances quota
New value for the key-pairs quota
New value for the fixed-ips quota
New value for the secgroups quota
New value for the injected-file-size quota
New value for the server-groups quota
New value for the server-group-members quota
New value for the floating-ips quota
New value for the injected-files quota
New value for the cores quota
New value for the injected-path-size quota
New value for the gigabytes quota
New value for the volumes quota
New value for the snapshots quota
Set quotas for a specific <volume-type>
New value for the networks quota
New value for the subnets quota
New value for the ports quota
New value for the routers quota
New value for the rbac-policies quota
New value for the vips quota
New value for the subnetpools quota
New value for the members quota
New value for the health-monitors quota