Module settings "description" field

I’m trying to figure out how to add a description to a settings field as can be seen in the screenshot below. I can’t figure out what magic to do… are there any examples?

You need to supply a .properties file in the same location as the PersistentRecord subclass you created, with entries for visible name and description for each field you’ve defined. Something like this:

ProducerThreads.Name=Maximum I/O Thread Count
ProducerThreads.Desc=The number of threads to allow in this device's I/O scanning, polling, and data producing processors.

(From my Ethernet/IP module)

Perfect! The magic I was missing was Desc. I tried Description, but should have thought to shorten it.

Thank you!