Problem Definition
At the moment, in our  documentation here, it says,

In Visual mode, you can still enter wiki markdown syntax as you add your content, and it'll be rendered exactly as it'll display when you save.

Which means that it will still render the syntax the way wiki markup renders it. In some cases, the users would need visual mode to simply show the strings exactly as users type it (without following how wiki markup renders it). For example, if the customer type \ followed by _, it will treat it as escape character and remove \ instead, while this is being used to identify directory and it's important to keep \. 

Suggested Solution
It would be great to have the option to allow visual mode to escape wiki markup rendering, and let the user get what they see/type.