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4 <TITLE>Definitions of terms used to describe Apache directives
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16 <H1 ALIGN="CENTER">Terms Used to Describe Apache Directives</H1>
19 Each Apache configuration directive is described using a common format
26 ><STRONG>Syntax:</STRONG></A> <EM>directive-name</EM> <EM>some args</EM>
31 ><STRONG>Default:</STRONG></A>
32 <SAMP><EM>directive-name default-value</EM></SAMP>
37 ><STRONG>Context:</STRONG></A> <EM>context-list</EM>
42 ><STRONG>Override:</STRONG></A> <EM>override</EM>
47 ><STRONG>Status:</STRONG></A> <EM>status</EM>
52 ><STRONG>Module:</STRONG></A> <EM>module-name</EM>
57 ><STRONG>Compatibility:</STRONG></A> <EM>compatibility notes</EM>
61 Each of the directive's attributes, complete with possible values
62 where possible, are described in this document.
65 <H2>Directive Terms</H2>
67 <LI><A HREF="#Syntax">Syntax</A>
69 <LI><A HREF="#Default">Default</A>
71 <LI><A HREF="#Context">Context</A>
73 <LI><A HREF="#Override">Override</A>
75 <LI><A HREF="#Status">Status</A>
77 <LI><A HREF="#Module">Module</A>
79 <LI><A HREF="#Compatibility">Compatibility</A>
84 <H2><A NAME="Syntax">Syntax</A></H2>
86 This indicates the format of the directive as it would appear in a
87 configuration file. This syntax is extremely directive-specific, so
88 refer to the text of the directive's description for details.
92 <H2><A NAME="Default">Default</A></H2>
94 If the directive has a default value (<EM>i.e.</EM>, if you omit it
95 from your configuration entirely, the Apache Web server will behave as
96 though you set it to a particular value), it is described here. If
97 there is no default value, this section should say
98 "<EM>None</EM>".
102 <H2><A NAME="Context">Context</A></H2>
104 This indicates where in the server's configuration files the directive
105 is legal. It's a comma-separated list of one or more of the following
109 <DT><STRONG>server config</STRONG>
111 <DD>This means that the directive may be used in the server
112 configuration files (<EM>e.g.</EM>, <SAMP>httpd.conf</SAMP>,
113 <SAMP>srm.conf</SAMP>, and <SAMP>access.conf</SAMP>), but
114 <STRONG>not</STRONG> within any <SAMP><VirtualHost></SAMP> or
115 <Directory> containers. It is not allowed in
116 <SAMP>.htaccess</SAMP> files at all.
120 <DT><STRONG>virtual host</STRONG>
122 <DD>This context means that the directive may appear inside
123 <SAMP><VirtualHost></SAMP> containers in the server
128 <DT><STRONG>directory</STRONG>
130 <DD>A directive marked as being valid in this context may be used
131 inside <SAMP><Directory></SAMP> containers in the server
136 <DT><STRONG>.htaccess</STRONG>
138 <DD>If a directive is valid in this context, it means that it can
139 appear inside <EM>per</EM>-directory <SAMP>.htaccess</SAMP> files.
140 It may not be processed, though depending upon the
151 The directive is <EM>only</EM> allowed within the designated context;
152 if you try to use it elsewhere, you'll get a configuration error that
153 will either prevent the server from handling requests in that context
154 correctly, or will keep the server from operating at all --
155 <EM>i.e.</EM>, the server won't even start.
158 The valid locations for the directive are actually the result of a
159 Boolean OR of all of the listed contexts. In other words, a directive
160 that is marked as being valid in "<SAMP>server config,
161 .htaccess</SAMP>" can be used in the <SAMP>httpd.conf</SAMP> file
162 and in <SAMP>.htaccess</SAMP> files, but not within any
163 <Directory> or <VirtualHost> containers.
167 <H2><A NAME="Override">Override</A></H2>
169 This directive attribute indicates which configuration override must
170 be active in order for the directive to be processed when it appears
171 in a <SAMP>.htaccess</SAMP> file. If the directive's
176 doesn't permit it to appear in <SAMP>.htaccess</SAMP> files, this
177 attribute should say "<EM>Not applicable</EM>".
180 Overrides are activated by the
182 HREF="core.html#allowoverride"
184 ><SAMP>AllowOverride</SAMP></A>
185 directive, and apply to a particular scope (such as a directory) and
186 all descendants, unless further modified by other
187 <SAMP>AllowOverride</SAMP> directives at lower levels. The
188 documentation for that directive also lists the possible override
193 <H2><A NAME="Status">Status</A></H2>
195 This indicates how tightly bound into the Apache Web server the
196 directive is; in other words, you may need to recompile the server
197 with an enhanced set of modules in order to gain access to the
198 directive and its functionality. Possible values for this attribute
202 <DT><STRONG>Core</STRONG>
204 <DD>If a directive is listed as having "Core" status, that
205 means it is part of the innermost portions of the Apache Web server,
206 and is always available.
210 <DT><STRONG>Base</STRONG>
212 <DD>A directive labeled as having "Base" status is
213 supported by one of the standard Apache modules which is compiled
214 into the server by default, and is therefore normally available
215 unless you've taken steps to remove the module from your configuration.
219 <DT><STRONG>Extension</STRONG>
221 <DD>A directive with "Extension" status is provided by one
222 of the modules included with the Apache server kit, but the module
223 isn't normally compiled into the server. To enable the directive
224 and its functionality, you will need to change the server build
225 configuration files and re-compile Apache.
229 <DT><STRONG>Experimental</STRONG>
231 <DD>"Experimental" status indicates that the directive is
232 available as part of the Apache kit, but you're on your own if you
233 try to use it. The directive is being documented for completeness,
234 and is not necessarily supported. The module which provides the
235 directive may or may not be compiled in by default; check the top of
236 the page which describes the directive and its module to see if it
237 remarks on the availability.
244 <H2><A NAME="Module">Module</A></H2>
246 This quite simply lists the name of the source module which defines
251 <H2><A NAME="Compatibility">Compatibility</A></H2>
253 If the directive wasn't part of the original Apache version 1
254 distribution, the version in which it was introduced should be listed
255 here. If the directive has the same name as one from the NCSA HTTPd
256 server, any inconsistencies in behaviour between the two should also
257 be mentioned. Otherwise, this attribute should say "<EM>No
258 compatibility issues.</EM>"
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