It's impossible to have a [WYSIWYG] editor in a wiki without using some additional technology, like javascript, applet or browser extension, but it's possible to have "almost wysiwyg" by carefully choosing the markup in the RawText, so that it is similar to the RenderedPage.

The most widespread example of MostlyWysiwyg is using the CamelCase to mark links in wikis. Another examples might be using "_" for __underline__, indentation for blockqutes, indented single asterisks for bullet lists and a row of dashes for a horizontal line.

MostlyWysiwyg has many advantages of [WYSIWYG], but without the technical limitations of the latter.