12.2 Emphasis and Monospace

You can make words ‘*bold*’, ‘/italic/’, ‘_underlined_’, ‘=verbatim=’ and ‘~code~’, and, if you must, ‘+strike-through+’. Text in the code and verbatim string is not processed for Org specific syntax; it is exported verbatim.

To turn off fontification for marked up text, you can set org-fontify-emphasized-text to nil. To narrow down the list of available markup syntax, you can customize org-emphasis-alist.