Possibly substantive LC issues

Do we have an official list of which LC issues we've determined 
definitely /aren't/ substantive, and which ones we've looked at and 
decided that they /might/ be or /definitely would be /substantive if 
accepted?  This is not quite the same as whether the issue is currently 
active, since (among other things) there are active issues we haven't 
looked at yet.

If there is no such list, could we maintain one, perhaps by marking them 
appropriately on the LC Issues list?

Thanks