gnus-summary-newsgroup-prefix

gnus-summary-newsgroup-prefix is a variable defined in `gnus-sum.el'.
Its value is

"=> "

Documentation:
*String prefixed to the Newsgroup field in the summary
line when using the option `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.