how to cancel limitation?

[Steven Woody]

i quite often use '/ a' or '/ s' to limit the summary buffer in a special
range.  while feeling happy with its results, i however have not find a way to
cacel the limitation after did the job, so to let current group display all its
articles, i have to go out and go back again. i believe there must be a command
to do that, can you tell me? thanks.

-
narke