http://www.wikicreole.org/wiki/Talk.ListsReasoning
List management is a tremendous pain in all wikis, the worst of manual tasks.  Anything that can be done to reduce the load, such as listing backlinks easily with a plugin in a page, is useful.

Also considering how wildly common surveys, polls, ranking and other forms of voting are in all social software, and how much advantage a wiki would have for fully supporting these functions, it seems unwise not to consider this in advance and integrate it with other lists, making it an ordinary low-overhead thing to let users decide ordering or ranking.

Given that need, it's useful to distinguish between three types of lists:
*those in strong order and explicitly numbered as a sequence of steps that all users are expected to agree on
*those in a strong but undecided, or proposed priority order that is subject to debate among all users, such as a list of candidates for a position that is being voted upon, in which case there may be a specific protocol for changing the order that isn't the same as the protocol for challenging a sequence, i.e. consensus isn't expected
*those in a very weak order or unordered state which can, like the strong order, be edited directly because it's amenable to debate and isn't making any decision

The use of proposed priority order is very common in wikis especially for votes.  As there are many ways to undermine a vote it would be useful at least to allow for a list style that automatically re-ordered or tally items based on, for instance, some ranking or vote system that acts as a plugin.  No need to use new characters, an overload could do, something like {{{ #* }}} to mean "present these in the order that the group agrees on by voting" and {{{ *# }}} to mean "keep these in the order defined but indicate the tally of votes for each one beside the option" or something like that.  This lets a page describing a decison or election be locked while users vote.  Even if all users can edit, anyone changing that structure is not going to mess up the plugin tallying the vote, unlike a standard wiki page, because the numbers are elsewhere.  Also it becomes much harder to fool naive users:  any change to the structure is unjustified during a vote since the plugin does the job of ordering at HTML presentation, so you'll spot anyone mucking around easily and can lock the vote-receiving structure if required.  Changing the list of option(s) would for instance invalidate the vote unless/until it was restored to a previous state.  Variants could support prefernence {{{ #*# }}} and allocation {{{ *#* }}} or other types of votes.  
-- Anonymous, 2007-02-05

What you are describing is totally up to the plugin you envision, and Creole has nothing to do with it. We certainly can't require such a plugin to be present in all wikis supporting Creole. Note that both input and output is up for the plugin creator to decide.
-- RadomirDopieralski, 2007-02-05

Reserving combinations of the two list characters for extensions of this kind is not the same as "requiring" any such thing to be supported.  Interpreting these extensions as ordinary ordered lists is perfectly valid default behaviour and it makes it very easy also to manually track the votes that are going on everywhere.  So there's utility to reserving these character combinations for this even without a plugin, and the default behaviour when there is no plugin at all present, is graceful enough:  it simply defaults to the way this is done now.

Plugin creators will flock in to do a better job if they see a lot of demand, and lists presented specifically as votes/ranks/polls/surveys will attract them to do a good job supporting the real need.

-- Anonymous, 2007-02-05

I don't think it is the role of Creole to encourage writing specific plugins. Personally I never ever encoutered the use cases you describe  in a wild on any wiki I know. Moreover, the markup you're proposing conflicts with existing Creole markup for mixed lists:

{{{
* first level bullet list
*# second level numbered list
}}}
-- RadomirDopieralski, 2007-02-05