org-emphasis-alist

org-emphasis-alist is a variable defined in `org.el'.
Its value is

(("*" bold)
 ("/" italic)
 ("_" underline)
 ("=" org-verbatim verbatim)
 ("~" org-code verbatim)
 ("+"
  (:strike-through t)))

Documentation:
Alist of characters and faces to emphasize text.
Text starting and ending with a special character will be emphasized,
for example *bold*, _underlined_ and /italic/. This variable sets the
marker characters and the face to be used by font-lock for highlighting
in Org-mode Emacs buffers.

You need to reload Org or to restart Emacs after customizing this.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 24.4 of Emacs.