From: Ken Coar
+>Module: mod_autoindex
+
The IndexOptions directive specifies the behavior of the directory indexing.
Option can be one of
@@ -577,7 +594,15 @@ indexing listings.
This will suppress the file size in fancy indexing listings.
-This default is that no options are enabled. If multiple IndexOptions
+
+There are some noticeable differences in the behaviour of this
+directive in recent (post-1.3.0) versions of Apache.
+
+The default is that no options are enabled. If multiple IndexOptions
could apply to a directory, then the most specific one is taken complete;
the options are not merged. For example:
+>Syntax: IndexOptions option option ...
+ (Apache 1.3.2 and earlier)
+
+Syntax: IndexOptions [+|-]option [+|-]option
+ ...
+ (Apache 1.3.3 and later)
+
Module: mod_autoindex
+Compatibility: '+/-' syntax and merging of multiple
+ IndexOptions directives is only available with
+ Apache 1.3.3 and later
+
+
then only
@@ -589,7 +614,56 @@ IndexOptions ScanHTMLTitles
</Directory>
ScanHTMLTitles
will be set for the /web/docs/spec
-directory.
+directory.
+
+Apache 1.3.3 introduced some significant changes in the handling of +IndexOptions directives. In particular, +
+IndexOptions FancyIndexing ScanHTMLTitles
.
+ +Whenever a '+' or '-' prefixed keyword is encountered, it is applied +to the current IndexOptions settings (which may have been +inherited from an upper-level directory). However, whenever an unprefixed +keyword is processed, it clears all incremental settings. Consider +the following example: +
+IndexOptions +ScanHTMLTitles -IconsAreLinks FancyIndexing
+
+IndexOptions +SuppressSize
+
+
+
+The net effect is equivalent to
+IndexOptions FancyIndexing +SuppressSize
, because
+the unprefixed FancyIndexing
discarded the incremental
+keywords before it, but allowed them to start accumulating again
+afterward.
+
+To unconditionally set the IndexOptions
for a
+particular directory, clearing the inherited settings, use
+
+IndexOptions None
+
+IndexOptions new-setting ...
+
+