unload-hook-features-list

unload-hook-features-list is a variable defined in `loadhist.el'.
Its value is

nil

• This variable is an alias for `unload-function-defs-list'.
• This variable is obsolete since 22.2;
  use `unload-function-defs-list' instead.

Documentation:
List of definitions in the Lisp library being unloaded.

This is meant to be used by `FEATURE-unload-function'; see the
documentation of `unload-feature' for details.