Variable: gnus-search-grep

gnus-search-grep is a variable without a source file.

This variable is obsolete since 25.1; use 'gnus-search-grep instead

Value

gnus-search-grep

Documentation

An abstract mixin class that can be added to
  local-filesystem search engines, providing an additional grep:
  search key. After the base engine returns a list of search
  results (as local filenames), an external grep process is used
  to further filter the results.