It might be worth to put a note here (using something similar to what we have on this [biom-format page](http://biom-format.org/documentation/biom_conversion.html) to delimit a note section) that Parameter names should be valid Python identifiers (e.g., no dashes in the name) so that ```Command.__call__``` can be run with named options instead of passing a dict. Having a simple code example here would also help illustrate this.

It's also worth noting that Parameter names must be unique for a given Command. We have a check in place that gives a meaningful error message, but still might be useful to make note of that here.