Explain better about abnormal hooks.

1 files changed, 14 insertions, 11 deletions

diff --git a/lispref/hooks.texi b/lispref/hooks.texi
index 18f8bcfcad5..046ac7cc5d5 100644
--- a/lispref/hooks.texi
+++ b/lispref/hooks.texi
@@ -11,19 +11,22 @@ functions to be called from within Emacs on suitable occasions.
 
 Most of these variables have names ending with @samp{-hook}.  They are
 @dfn{normal hooks}, run by means of @code{run-hooks}.  The value of such
-a hook is a list of functions.  The recommended way to put a new
-function on such a hook is to call @code{add-hook}.  @xref{Hooks}, for
-more information about using hooks.
+a hook is a list of functions; the functions are called with no
+arguments and their values are completely ignored.  The recommended way
+to put a new function on such a hook is to call @code{add-hook}.
+@xref{Hooks}, for more information about using hooks.
 
-The variables whose names end in @samp{-function} have single functions
-as their values.  Usually there is a specific reason why the variable is
-not a normal hook, such as the need to pass arguments to the function.
-(In older Emacs versions, some of these variables had names ending in
-@samp{-hook} even though they were not normal hooks.)
+The variables whose names end in @samp{-hooks} or @samp{-functions} are
+usually @dfn{abnormal hooks}; their values are lists of functions, but
+these functions are called in a special way (they are passed arguments,
+or their values are used).  A few of these variables are actually normal
+hooks which were named before we established the convention that normal
+hooks' names should end in @samp{-hook}.
 
-The variables whose names end in @samp{-hooks} or @samp{-functions} have
-lists of functions as their values, but these functions are called in a
-special way (they are passed arguments, or else their values are used).
+The variables whose names end in @samp{-function} have single functions
+as their values.  (In older Emacs versions, some of these variables had
+names ending in @samp{-hook} even though they were not normal hooks;
+however, we have renamed all of those.)
 
 @c !!! need  xref  to where each hook is documented or else document it
 @c by specifying what is expected, and when it is called relative to