said to @dfn{match}.
Each style may contain an arbitrary amount of @dfn{attributes}. Each
-attribute consists of a @code{(@var{name} @var{value})} pair. The
-attribute name can be one of:
+attribute consists of a @code{(@var{name} @var{value})} pair. In
+addition, you can also use the @code{(@var{name} :file @var{value})}
+form or the @code{(@var{name} :value @var{value})} form. Where
+@code{:file} signifies @var{value} represents a file name and its
+contents should be used as the attribute value, @code{:value} signifies
+@var{value} does not represent a file name explicitly. The attribute
+name can be one of:
@itemize @bullet
@item @code{signature}
A file containing credentials used to log in on servers. The format is
(almost) the same as the @code{ftp} @file{~/.netrc} file. See the
variable @code{nntp-authinfo-file} for exact syntax; also see
-@ref{NNTP}.
+@ref{NNTP}. An example of an .authinfo line for an IMAP server, is:
+
+@example
+machine students.uio.no login larsi password geheimnis port imap
+@end example
+
+Note that it should be @code{port imap}, or @code{port 143}, if you
+use a @code{nnimap-stream} of @code{tls} or @code{ssl}, even if the
+actual port number used is port 993 for secured IMAP. For
+convenience, Gnus will accept @code{port imaps} as a synonym of
+@code{port imap}.
@item nnimap-need-unselect-to-notice-new-mail
@vindex nnimap-need-unselect-to-notice-new-mail