Re: What's NOV? Should gnus-nov-is-evil be set to t?

[Katsumi Yamaoka]

>>>>> Leo wrote:
> On 2007-09-14 00:27 +0100, Katsumi Yamaoka wrote:

>> I'll do it someday, even though I'm not a good English writer. ;-)

> I am non-native speaker myself.

OK.  I've added this:

(info "(gnus)Slow/Expensive Connection")
,----
|`gnus-nov-is-evil'
|     This one has to be _always_ `nil' (which is the default).  If you
|     need not to use NOV (see below) with the `nntp' back end for
|     example (*note Crosspost Handling::), set `nntp-nov-is-evil' to a
|     non-`nil' value instead of setting this.  But you normally have no
|     need to set `nntp-nov-is-evil' since Gnus by itself will detect
|     whether the NNTP server supports NOV.  Anyway, grabbing article
|     headers from the NNTP server will not be very fast if you tell
|     Gnus not to use NOV.
|
|     As the variables for the other back ends, there are
|     `nndiary-nov-is-evil', `nndir-nov-is-evil',
|     `nnfolder-nov-is-evil', `nnimap-nov-is-evil', `nnml-nov-is-evil',
|     `nnspool-nov-is-evil', and `nnwarchive-nov-is-evil'.  Note that a
|     non-`nil' value for `gnus-nov-is-evil' overrides all those
|     variables.
|
|What's NOV?
|
|   NOV stands for News OverView, which provide data containing the
|condensed header information of articles.  They are what the server
|makes; in the `nntp' back end Gnus uses the ones that the NNTP server
|makes, but Gnus makes them by itself in the server like `nnml' which
|Gnus performs.  The NOV data consist of one or more text lines (*note
|Motion by Text Lines: (elisp)Text Lines.) where each line has the header
|information of one article.  The header information is a tab-separated
|series of the header's contents including an article number, a subject,
|an author, a date, a message-id, references, etc.
|
|   Those data enable Gnus to generate summary lines fast.  However, if
|the server does not support NOV or you disable it purposely or for some
|reason, Gnus will try to generate the header information by parsing
|article's header one by one.  It will take time.  Therefore, it is not
|usually a good idea to set `*-nov-is-evil' to a non-`nil' value unless
|there is such a reason that the server makes wrong NOV data.
`----

See you next week.