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<TITLE>Definitions of terms used to describe Apache directives
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<H1 ALIGN="CENTER">Terms Used to Describe Apache Directives</H1>
<P>
Each Apache configuration directive is described using a common format
that looks like this:
</P>
<DL>
<DD><A
HREF="#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> <EM>directive-name</EM> <EM>some args</EM>
<BR>
<A
HREF="#Default"
REL="Help"
><STRONG>Default:</STRONG></A>
<SAMP><EM>directive-name default-value</EM></SAMP>
<BR>
<A
HREF="#Context"
REL="Help"
><STRONG>Context:</STRONG></A> <EM>context-list</EM>
<BR>
<A
HREF="#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>override</EM>
<BR>
<A
HREF="#Status"
REL="Help"
><STRONG>Status:</STRONG></A> <EM>status</EM>
<BR>
<A
HREF="#Module"
REL="Help"
><STRONG>Module:</STRONG></A> <EM>module-name</EM>
<BR>
<A
HREF="#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> <EM>compatibility notes</EM>
</DD>
</DL>
<P>
Each of the directive's attributes, complete with possible values
where possible, are described in this document.
</P>
<H2>Directive Terms</H2>
<UL>
<LI><A HREF="#Syntax">Syntax</A>
</LI>
<LI><A HREF="#Default">Default</A>
</LI>
<LI><A HREF="#Context">Context</A>
</LI>
<LI><A HREF="#Override">Override</A>
</LI>
<LI><A HREF="#Status">Status</A>
</LI>
<LI><A HREF="#Module">Module</A>
</LI>
<LI><A HREF="#Compatibility">Compatibility</A>
</LI>
</UL>
<HR>
<H2><A NAME="Syntax">Syntax</A></H2>
<P>
This indicates the format of the directive as it would appear in a
configuration file. This syntax is extremely directive-specific,
and is described in detail in the directive's definition.
Generally, the directive name is followed by a series of one or
more arguments. Optional arguments are enclosed in square brackets.
Where an argument can take on more than one possible value, possible
values are separated by a vertical bar. Literal text is presented
in the default font, while argument-types for which substitution
is necessary are emphasized. Directives which can take a variable
number of arguments will end in "..." indicating that the last
argument is repeated.
</P>
<HR>
<H2><A NAME="Default">Default</A></H2>
<P>
from your configuration entirely, the Apache Web server will behave as
though you set it to a particular value), it is described here. If
there is no default value, this section should say
"<EM>None</EM>".
</P>
<HR>
<H2><A NAME="Context">Context</A></H2>
<P>
This indicates where in the server's configuration files the directive
is legal. It's a comma-separated list of one or more of the following
values:
</P>
<DL>
<DT><STRONG>server config</STRONG>
</DT>
<DD>This means that the directive may be used in the server
<STRONG>not</STRONG> within any <SAMP><VirtualHost></SAMP> or
<Directory> containers. It is not allowed in
<SAMP>.htaccess</SAMP> files at all.
<P>
</P>
</DD>
<DT><STRONG>virtual host</STRONG>
</DT>
<DD>This context means that the directive may appear inside
<SAMP><VirtualHost></SAMP> containers in the server
configuration files.
<P>
</P>
</DD>
<DT><STRONG>directory</STRONG>
</DT>
<DD>A directive marked as being valid in this context may be used
inside <SAMP><Directory></SAMP>,
<SAMP><Location></SAMP>, and <SAMP><Files></SAMP>
containers in the server configuration files, subject to the
restrictions outlined in <A HREF="/sections.html">How Directory,
Location and Files sections work</A>.
<P>
</P>
</DD>
<DT><STRONG>.htaccess</STRONG>
</DT>
<DD>If a directive is valid in this context, it means that it can
appear inside <EM>per</EM>-directory <SAMP>.htaccess</SAMP> files.
It may not be processed, though depending upon the
<A
HREF="#Override"
REL="Help"
>overrides</A>
currently active.
<P>
</P>
</DD>
</DL>
<P>
The directive is <EM>only</EM> allowed within the designated context;
if you try to use it elsewhere, you'll get a configuration error that
will either prevent the server from handling requests in that context
correctly, or will keep the server from operating at all --
</P>
<P>
The valid locations for the directive are actually the result of a
Boolean OR of all of the listed contexts. In other words, a directive
that is marked as being valid in "<SAMP>server config,
and in <SAMP>.htaccess</SAMP> files, but not within any
<Directory> or <VirtualHost> containers.
</P>
<HR>
<H2><A NAME="Override">Override</A></H2>
<P>
This directive attribute indicates which configuration override must
be active in order for the directive to be processed when it appears
in a <SAMP>.htaccess</SAMP> file. If the directive's
<A
HREF="#Context"
REL="Help"
>context</A>
doesn't permit it to appear in <SAMP>.htaccess</SAMP> files, this
attribute should say "<EM>Not applicable</EM>".
</P>
<P>
Overrides are activated by the
<A
HREF="core.html#allowoverride"
REL="Help"
><SAMP>AllowOverride</SAMP></A>
directive, and apply to a particular scope (such as a directory) and
all descendants, unless further modified by other
<SAMP>AllowOverride</SAMP> directives at lower levels. The
documentation for that directive also lists the possible override
names available.
</P>
<HR>
<H2><A NAME="Status">Status</A></H2>
<P>
This indicates how tightly bound into the Apache Web server the
directive is; in other words, you may need to recompile the server
with an enhanced set of modules in order to gain access to the
directive and its functionality. Possible values for this attribute
are:
</P>
<DL>
<DT><STRONG>Core</STRONG>
</DT>
<DD>If a directive is listed as having "Core" status, that
means it is part of the innermost portions of the Apache Web server,
and is always available.
<P>
</P>
</DD>
<DT><STRONG>MPM</STRONG>
</DT>
<DD>A directive labeled as having "MPM" status is
This type of directive will be available if and only if you are
using one of the MPMs lised on the <a href="#Module">Module</a>
line of the directive definition.
<P>
</P>
</DD>
<DT><STRONG>Base</STRONG>
</DT>
<DD>A directive labeled as having "Base" status is
supported by one of the standard Apache modules which is compiled
into the server by default, and is therefore normally available
unless you've taken steps to remove the module from your configuration.
<P>
</P>
</DD>
<DT><STRONG>Extension</STRONG>
</DT>
<DD>A directive with "Extension" status is provided by one
of the modules included with the Apache server kit, but the module
isn't normally compiled into the server. To enable the directive
and its functionality, you will need to change the server build
configuration files and re-compile Apache.
<P>
</P>
</DD>
<DT><STRONG>Experimental</STRONG>
</DT>
<DD>"Experimental" status indicates that the directive is
available as part of the Apache kit, but you're on your own if you
try to use it. The directive is being documented for completeness,
and is not necessarily supported. The module which provides the
directive may or may not be compiled in by default; check the top of
the page which describes the directive and its module to see if it
remarks on the availability.
<P>
</P>
</DD>
</DL>
<HR>
<H2><A NAME="Module">Module</A></H2>
<P>
This quite simply lists the name of the source module which defines
the directive.
</P>
<HR>
<H2><A NAME="Compatibility">Compatibility</A></H2>
<P>
If the directive wasn't part of the original Apache version 1
distribution, the version in which it was introduced should be listed
here. If the directive has the same name as one from the NCSA HTTPd
server, any inconsistencies in behaviour between the two should also
be mentioned. Otherwise, this attribute should say "<EM>No
compatibility issues.</EM>"
</P>
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