Honestly, I couldn't find an explanation of the difference between these two list states in the help or on the forums - maybe I didn't look hard enough, but instead I tried experimenting. Here's what I've concluded:
By "Hide" - I mean going into the List settings, and clicking the "hide" link for a specific list.
By Archive - I mean going into the List settings, selecting one or more lists, and choosing Archive from the "More Actions ..." menu ...
If you Hide or Archive a list, the list will be hidden from the tabs, or list of lists (if using A Bit Better RTM). So far these behave the same - but, the magic is in how the tasks on those lists are handled differently.
Tasks on "hidden" lists, still show up in searches, and All Tasks. Just the list itself doesn't show up.
Tasks that are on "archived" lists, will not show up in searches or All Tasks. You can search "archived" tasks by adding "includeArchived:true" in the advanced search field.
How can this be handy?
A hidden list might be useful for a list you don't use very often, like a christmas wish list - because you can still reference it, find stuff in it, etc. You can still list the contents of a hidden list using the advanced search syntax "list:listname".
An archived list is most useful for projects that you've completed, and don't want to show up in searches, unless you specifically ask for them.
In both cases, the tasks on them (completed, and uncompleted) stay around forever unless you explicitly delete them.
Did I get something wrong? Chime in and let me know - I'm just trying to share what I've learned for other RTM'ers who can use the knowledge.
Posted at 4:53am on October 8, 2013