Each of the following examples is an example target settings file. On startup, 
pazpar2 will read any number of these files recursively from a directory hierarchy.
Explanations for the examples below.

The following file explicitly sets name=value for a whole bunch of targets for a
bunch of users.. I don't imagine this format will be used much for human
entry, but it might be used to export settings from a relational database.. it is
also there as one extreme form of a generic format.

If user is omitted, the setting applies to any user. For target, there are two wildcard
forms: * matches any target not otherwise matched, and xx/* matches any database on a given
host. A setting for an explicit host/db always overrides a wildcard setting.

<settings>
  <set target="xx" name="xx" value="xx" user="xx"/>
  <set target="xx" name="xx" value="xx" user="xx"/>
  <set target="xx" name="xx" value="xx" user="xx"/>
</settings>

More useful, you can group a number of settings about a target into one file like this.
This comes closer to the conventional target setting files we're used to. 

<settings target="xx">
  <set name="xx" value="xx"/>
  <set name="xx" value="xx"/>
  <set name="xx" value="xx"/>
</settings>

This file sets a number of name=value pairs for a list of targets. A typical example might
be to associate all these targets with a specific category or type, or to otherwise make
them part of a set -- like 'all full-text', 'all free-access', etc.

<settings name="xx" value="xx">
  <set target="xx"/>
  <set target="xx"/>
  <set target="xx"/>
  <set target="xx"/>
</settings>

Here's the shortest possible file.. it sets one name=value for one target

<settings target="xx" name="xx" value="xx" user="xx"/>

This sets different values for a given named setting (attribute) for one target.

<settings name="xx" target="xx">
  <set value="xx"/>
  <set value="xx"/>
  <set value="xx"/>
</settings>

This sets different values for one attribute for different targets 

<settings name="xx">
  <value>xx</value>
  <value>xx</value>
  <set target="xx"/>
  <set target="xx"/>
  <set target="xx"/>
</settings>

This sets one or more named values for a set of targets.

<settings>
  <target>xx</target>
  <target>xx</target>
  <target>xx</target>
  <set name="xx" value="xx"/>
  <set name="xx" value="xx"/>
</settings>

This is a more concrete example.. it allows specific users access to a given target.

<settings name="pz:allow" target="xx" value="yes">
  <set user="xx"/>
  <set user="xx"/>
  <set user="xx"/>
</settings>

While this default setting disallows access to anything for everybody not otherwise
permitted...

// Whitelist default -- disallow all access
<settings name="pz:allow" target="*" value="no"/>

.. except these 'free' targets which are open to anyone.

// Except these ones
<settings name="pz:allow" value="yes">
  <set target="xx"/>
  <set target="xx"/>
  <set target="xx"/>
</settings>

The setting below sets a default record normalization stylesheet. Yes, values can be simple
strings, or they can be XML trees.

<settings xmlns="http://www.indexdata.com/pazpar2/1" target="*" name="pz:normalize">
  <set>
    <xsl:stylesheet xmlns:xsl="xxx" ..>
    </xsl:stylesheet>
  </set>
</settings>