You can make words *bold*, /italic/, _underlined_,
~code~, and, if you must, ‘+strike-through+’. Text
in the code and verbatim string is not processed for Org mode specific
syntax, it is exported verbatim.
To turn off fontification for marked up text, you can set
nil. To narrow down the list of
available markup syntax, you can customize
org-emphasis-alist. To fine
tune what characters are allowed before and after the markup characters, you
org-emphasis-regexp-components. Beware that changing one of
the above variables will no take effect until you reload Org, for which you
may need to restart Emacs.