org-use-sub-superscripts

org-use-sub-superscripts is a variable defined in `org.el'.
Its value is

t

Documentation:
Non-nil means interpret "_" and "^" for display.

If you want to control how Org exports those characters, see
`org-export-with-sub-superscripts'. `org-use-sub-superscripts'
used to be an alias for `org-export-with-sub-superscripts' in
Org <8.0, it is not anymore.

When this option is turned on, you can use TeX-like syntax for
sub- and superscripts within the buffer. Several characters after
"_" or "^" will be considered as a single item - so grouping
with {} is normally not needed. For example, the following things
will be parsed as single sub- or superscripts:

10^24 or 10^tau several digits will be considered 1 item.
10^-12 or 10^-tau a leading sign with digits or a word
x^2-y^3 will be read as x^2 - y^3, because items are
terminated by almost any nonword/nondigit char.
x_{i^2} or x^(2-i) braces or parenthesis do grouping.

Still, ambiguity is possible. So when in doubt, use {} to enclose
the sub/superscript. If you set this variable to the symbol `{}',
the braces are *required* in order to trigger interpretations as
sub/superscript. This can be helpful in documents that need "_"
frequently in plain text.

You can customize this variable.

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