Controller Not Firing When Using URL Param - angularjs

Question

I'm not clear why this isn't functioning. The rest of my code - sans the URL Param-based routing is working fine, I've tested that all. However, when I tried to include a URL argument in my url (base.url/route/:param) the '.otherwise' element of my routeProvider is firing instead of the appropriate controller designated in the routeProvider.
Here's the relevant bits of code:
module.config
app.config(function($routeProvider){
//http://docs.angularjs.org/tutorial/step_07
$routeProvider
.when('/home',
{
templateUrl: 'app/partials/home.html',
controller: 'HomeController'
})
.when('/implementation-reference/:ref-scope',
{
templateUrl: 'app/partials/topic_tpl.html',
controller: 'ImplReference'
})
.when('/projects',
{
templateUrl: 'app/partials/project_list_tpl.html',
controller: 'Projects'
})
.when ('/site-help',
{
templateUrl: 'app/partials/site-help.html'
})
.otherwise(
{
templateUrl: 'app/partials/404.html'
})
});
module.controller
app.controller('ImplReference', function($scope, $routeParams) {
alert('hi');
});
I get my 404 page when going to /implementation-reference/whatever.
Any ideas why I don't see the alert I put at the beginning of my controller, nor see any errors in the console?

Answer 1

As best as I can tell, the issue lay in use a dash in the param as defined in RouteProvider. I originally had:
.when('/implementation-reference/:ref-scope',
{
templateUrl: 'app/partials/topic_tpl.html',
controller: 'ImplReference'
})
when I changed it to this:
.when('/implementation-reference/:ref',
{
templateUrl: 'app/partials/topic_tpl.html',
controller: 'ImplReference'
})
...suddenly everything works fine.
I noticed this after adding a controller to the 'otherwise' that showed me the $route information. After drilling through it, I saw that the regex on the pre-defined route which had the param was only working on the part before the dash.
I've been mystified by this for hours, and can't imagine how this isn't documented more clearly somewhere. Perhaps this is some newbie mistake (I am new to this).