vSphere 5.5 User Defined Storage Capability

Is it possible to create a user-defined Storage Capability in vSphere 5.5?

I'm trying to create a Storage Policy and when I get to the 'Rule Set 1' section, the only option for capabilities is 'None'. I remember in 5.0 in the VI Client, there was an option to "Manage Storage Capabilities" and create a user-defined capability. Is this an option in 5.5 in the web client?

Thanks,

Scott