Currently, with numbered and unnumbered lists, you can have sublists, but you cannot easily "go back to the previous level" after a sublist.

• You can start a new list item.
• You can use an indent : to continue your previous level after the sublist, but (depending on installation, skin, and local CSS) that does not always render as intended.
• you can put a <br /> plus a <span> or <div> with some arbitrary indentation at the end of your last sublist item. Besides being a structural sin, that hardly renders as intended with many skins, and browsers.
• You can wrap your sublist in a <div> container, but you usually need to know many peculiaritites of CSS and browser oddities in order to make it really work.

I want the latter be taken care of with a simple wikitext syntax, basically signalling:
1 - "continue with, or return to a previous level" or else
2 - "omit list tag, and do not increment count"
whatever the implementor chooses.

I clearly favorize solution 1 since it preserves structure, thus giving more logical HTML.

Since having "-" (minus, standard dash) immediately behind a wikitext list designator or indentation mark (*#:;) is fairly uncommon, I suggest extending wikitext syntax by
these:

All of them terminate sublists/indentation up to the level of the *#:; preceeding the - and continue the last block or item on that level without starting a new list item or block.

Sample:

# Here starts number one, having:
#* a subitem
#* another subitem
#** with a sub-subitem
#- and a continuation on the #1 level behind all subitems.
# Here starts nuber two, now.

If a list item or block is to begin with a minus sign or dash, this syntax must be used:

* -       unordered list item beginning with a dash or minus
# -same-  ordered list item beginning with a dash or minus
: -16 km  indented block beginning with a minus sign
; -       start of definition list label with minus or dash

If - is not seen as a good choice, I suggest _ (underscore) as another possible candidate. Also . (dot) might be worth considering.

Version: unspecified
Severity: enhancement
URL: bugsmash