allout-flattened-numbering-abbreviation

allout-flattened-numbering-abbreviation is a variable defined in `allout.el'.
Its value is

nil

Documentation:
If non-nil, `allout-flatten-exposed-to-buffer' abbreviates topic
numbers to minimal amount with some context. Otherwise, entire
numbers are always used.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 24.1 of Emacs.