gnus-summary-to-prefix
gnus-summary-to-prefix is a variable defined in `gnus-sum.el
'.Its value is
"-> "
Documentation:
*String prefixed to the To field in the summary line when
using `gnus-ignored-from-addresses'.
You can customize this variable.
This variable was introduced, or its default value was changed, in version 22.1 of Emacs.