As per the suggestion by Nisse Engström (Many thanks) Ill post my solution here:
Having hunted around for an answer to this question for quite a while I have found a working solution and post it here in the hope that others might find this helpful.
The objective was to allow logged in users to see an articles list which only included their own articles and those of the SuperUser - they should only be able to edit their own articles.
To make this work the setup is as follows:
Default Install and using the Protostar template.
Override the file: "com_content/category/default_articles.php"
Around line 135 you can see the following line:
foreach ($this->items as $i => $article)
Directly below this line I have added the following code (Note that user 232 is my SuperUser - yours may have a different ID):
if ($this->items[$i]->created_by == JFactory::getUser()->id || $this->items[$i]->created_by == JFactory::getUser(232)->id) :
This is closed again on line 261 with a standard 'endif'. Note that this is directly above the closing 'endforeach' that started around line 135.
The Result
Is precisely what I wanted to see. Logged in users can now only see their own articles (and those of the Superuser, although they cannot edit these), and can submit new articles.
With a little tweaking of permissions each user can now create, edit, publish and trash only their own articles.
I have no idea if this is the "Right" way to achieve this result, but it works exactly as I wanted it to, and I am more than happy for experienced users to show alternative methods.
Possible future issue
This code is fired as Joomla loads the list of articles and as such will be fired many, many times as more and more users create more and more articles. Perhaps this will cause a slow down?
Anyway.....
