Need clarification on the need for a Single section being created
There are probably other points that can be added to this, but here are a few...


If you deleted the Single, and there was no change when the template is viewed, then you probably didn't need the Single. Were there any fields assigned to the Single, and were those fields referenced in the template? If the answer is "no", then the Single was definitely extraneous.
You can make a template hidden by prefixing the template name with an underscore: /rec/_list.html. This makes the template invisible on the front-end, unless it's being called up through a Single/Channel/Structure. Without the underscore, any template can be viewed directly. (Worth noting that the underscore can also be applied to the folder name, hiding all templates inside that folder.)


In summary, the value of a Single is to be able to manage your content via the Control Panel. Whatever dynamic data is stored in your Single will be pulled into your template. If you have no dynamic data, then the Single is unnecessary.