You can't do a comma-separated list like you're trying to do above. Since you're using Joomla content there, I'd suggest not creating custom objects at all. You should create Joomla - Content objects, if possible. Then, you can select the category (or categories) that the objects should apply to. Once that's done, you'll be able to perform an action on any of the articles that fall within those categories.
If you need to create an object on a per-article basis, then that's what you'll have to do.. create a new object for each article. Please note, the less specific you are, the more pages the object will apply to. So, you may be able to do something like:
option=com_content
view=article
Itemid=123
That would apply to any articles in a specific menu item, and that may work better for you.
I hope that helps explain, but if not, just let us know and we'll help however we can.
Thanks,
Alex
Automatic Actions for Open Graph, and multiple id's
