Reference 1: http://www.mingw.org/MinGWiki/index.php/TextFormattingRules
Reference 2: http://www.mediawiki.org/wiki/Help:Formatting

Copying and Pasting from old to new

• Goto an existing old MinGWiki page
• execute the login function
• click the edit button
• click the mouse into the edit box
• press the Ctrl-A keyboard action to select all text in the input form
• Now Create content and choose New MinGWiki.
• If not already provided, enter the title from the old MinGWiki page
• Enter an appropriate tag (a.k.a. category or term) for the page
• In the "Body" of the form now entry Ctrl-V to paste the previous body.
• You may now "Save" the document at the bottom of the form but you are far from done.

Converting from old to new format

• Find all %%% markup and remove them. If you need line breaks enter <br/> instead.
• Titles in the old format used ! or !! or !!! for small, medium, and large. The new format uses a =, ==, ===, ====, ===== and ====== to represent decreasing levels of header. I suggest using ===== for !, === for !! and == for !!! but in the end use what looks best to you.