When using the 'firefly' backend to afw.display, a "hostname" option is supposed to be available in the getDisplay() call. It does not work.

Action: either remove it from the documentation, or fix it.

Think again about whether supplying the url= option is better/easier or worse than the hostname= option, in terms of the maintainability of any overrides users may perform with these options.

The aim as always is for the normal use cases to be covered without any use of these options.