gnus: Process/Prefix

 
 9.1 Process/Prefix
 ==================
 
 Many functions, among them functions for moving, decoding and saving
 articles, use what is known as the “Process/Prefix convention”.
 
    This is a method for figuring out what articles the user wants the
 command to be performed on.
 
    It goes like this:
 
    If the numeric prefix is N, perform the operation on the next N
 articles, starting with the current one.  If the numeric prefix is
 negative, perform the operation on the previous N articles, starting
 with the current one.
 
    If ‘transient-mark-mode’ in non-‘nil’ and the region is active, all
 articles in the region will be worked upon.
 
    If there is no numeric prefix, but some articles are marked with the
 process mark, perform the operation on the articles marked with the
 process mark.
 
    If there is neither a numeric prefix nor any articles marked with the
 process mark, just perform the operation on the current article.
 
    Quite simple, really, but it needs to be made clear so that surprises
 are avoided.
 
    Commands that react to the process mark will push the current list of
 process marked articles onto a stack and will then clear all process
 marked articles.  You can restore the previous configuration with the ‘M
 P y’ command (SeeSetting Process Marks).
 
    One thing that seems to shock & horrify lots of people is that, for
 instance, ‘3 d’ does exactly the same as ‘d’ ‘d’ ‘d’.  Since each ‘d’
 (which marks the current article as read) by default goes to the next
 unread article after marking, this means that ‘3 d’ will mark the next
 three unread articles as read, no matter what the summary buffer looks
 like.  Set ‘gnus-summary-goto-unread’ to ‘nil’ for a more
 straightforward action.
 
    Many commands do not use the process/prefix convention.  All commands
 that do explicitly say so in this manual.  To apply the process/prefix
 convention to commands that do not use it, you can use the ‘M-&’
 command.  For instance, to mark all the articles in the group as
 expirable, you could say ‘M P b M-& E’.