+--------+ | +---+
| **|log+-Node
| * +---+
| * +----+
| +------+ **|mail+-Node
+-+action|** +----+ +-busy-Node
---- contains +------+ * +-----+ |
**|proxy+----+-noanswer-Node
**** substitutes * +-----+ |
* +--------+ +-failure-Node
**|redirect| |
* +--------+ +-redirection-Node
* +------+ |
*|reject| +-default-Node
+------+
Figure 31: The structure of the XML schema for CPL
BEGIN
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema targetNamespace="urn:ietf:params:xml:ns:cpl"
xmlns="urn:ietf:params:xml:ns:cpl"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
elementFormDefault="qualified"
attributeFormDefault="unqualified">
<xs:complexType name="TopLevelActionType" abstract="true">
<xs:group ref="Node"/>
</xs:complexType>
<xs:element name="toplevelaction" type="TopLevelActionType"/>
<xs:complexType name="ActionType" abstract="true"/>
<xs:element name="action" type="ActionType"/>
<xs:complexType name="SwitchType" abstract="true"/>
<xs:element name="switch" type="SwitchType"/>
<xs:complexType name="ModifierType" abstract="true"/>
<xs:element name="modifier" type="ModifierType"/>
<xs:element name="location" type="LocationType"
substitutionGroup="modifier"/>
<xs:element name="lookup" type="LookupType"
substitutionGroup="modifier"/>
<xs:element name="remove-location" type="RemoveLocationType"
substitutionGroup="modifier"/>
<xs:element name="sub" type="SubAction"/>
<xs:group name="Node">
<xs:choice>
<xs:element ref="switch" minOccurs="0" maxOccurs="1"/>
<xs:element ref="modifier" minOccurs="0" maxOccurs="1"/>
<xs:element ref="sub" minOccurs="0" maxOccurs="1"/>
<xs:element ref="action" minOccurs="0" maxOccurs="1"/>
</xs:choice>
</xs:group>
<xs:complexType name="OtherwiseAction">
<xs:group ref="Node"/>
</xs:complexType>
<xs:complexType name="NotPresentAction">
<xs:group ref="Node"/>
</xs:complexType>
<xs:simpleType name="YesNoType">
<xs:restriction base="xs:NMTOKEN">
<xs:enumeration value="yes"/>
<xs:enumeration value="no"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType name="StatusType">
<xs:union>
<xs:simpleType>
<xs:restriction base="xs:NMTOKEN">
<xs:enumeration value="busy"/>
<xs:enumeration value="notfound"/>
<xs:enumeration value="reject"/>
<xs:enumeration value="error"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType>
<xs:restriction base="xs:string"/>
</xs:simpleType>
</xs:union>
</xs:simpleType>
<xs:simpleType name="OrderingType">
<xs:restriction base="xs:NMTOKEN">
<xs:enumeration value="parallel"/>
<xs:enumeration value="sequential"/>
<xs:enumeration value="first-only"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType name="AddressFieldType">
<xs:union>
<xs:simpleType>
<xs:restriction base="xs:NMTOKEN">
<xs:enumeration value="origin"/>
<xs:enumeration value="destination"/>
<xs:enumeration value="original-destination"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType>
<xs:restriction base="xs:string"/>
</xs:simpleType>
</xs:union>
</xs:simpleType>
<xs:simpleType name="AddressSubfieldType">
<xs:union>
<xs:simpleType>
<xs:restriction base="xs:NMTOKEN">
<xs:enumeration value="address-type"/>
<xs:enumeration value="user"/>
<xs:enumeration value="host"/>
<xs:enumeration value="port"/>
<xs:enumeration value="tel"/>
<xs:enumeration value="display"/>
<xs:enumeration value="password"/>
<xs:enumeration value="alias-type"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType>
<xs:restriction base="xs:string"/>
</xs:simpleType>
</xs:union>
</xs:simpleType>
<xs:complexType name="AddressType">
<xs:annotation>
<xs:documentation>Exactly one of the three attributes must
appear</xs:documentation>
</xs:annotation>
<xs:group ref="Node"/>
<xs:attribute name="is" type="xs:string" use="optional"/>
<xs:attribute name="contains" type="xs:string" use="optional">
<xs:annotation>
<xs:documentation>for "display" only</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="subdomain-of" type="xs:string"
use="optional">
<xs:annotation>
<xs:documentation>for "host", "tel" only</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:anyAttribute namespace="##any" processContents="lax"/>
</xs:complexType>
<xs:complexType name="AddressSwitchType">
<xs:complexContent>
<xs:extension base="SwitchType">
<xs:sequence>
<xs:element name="address" type="AddressType" minOccurs="0"
maxOccurs="unbounded"/>
<xs:sequence minOccurs="0">
<xs:element name="not-present" type="NotPresentAction"/>
<xs:element name="address" type="AddressType"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
<xs:element name="otherwise" type="OtherwiseAction"
minOccurs="0"/>
</xs:sequence>
<xs:attribute name="field" type="AddressFieldType"
use="required"/>
<xs:attribute name="subfield" type="AddressSubfieldType"
use="optional"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:element name="address-switch" type="AddressSwitchType"
substitutionGroup="switch"/>
<xs:simpleType name="StringFieldType">
<xs:restriction base="xs:NMTOKEN">
<xs:enumeration value="subject"/>
<xs:enumeration value="organization"/>
<xs:enumeration value="user-agent"/>
<xs:enumeration value="display"/>
</xs:restriction>
</xs:simpleType>
<xs:complexType name="StringType">
<xs:group ref="Node"/>
<xs:attribute name="is" type="xs:string" use="optional"/>
<xs:attribute name="contains" type="xs:string" use="optional"/>
<xs:anyAttribute namespace="##any" processContents="lax"/>
</xs:complexType>
<xs:complexType name="StringSwitchType">
<xs:complexContent>
<xs:extension base="SwitchType">
<xs:sequence>
<xs:element name="string" type="StringType" minOccurs="0"
maxOccurs="unbounded"/>
<xs:sequence minOccurs="0">
<xs:element name="not-present" type="NotPresentAction"/>
<xs:element name="string" type="StringType" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
<xs:element name="otherwise" type="OtherwiseAction"
minOccurs="0"/>
</xs:sequence>
<xs:attribute name="field" type="StringFieldType"
use="required">
<xs:annotation>
<xs:documentation>Strings are matched as case-insensitive
Unicode strings.</xs:documentation>
</xs:annotation>
</xs:attribute>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:element name="string-switch" type="StringSwitchType"
substitutionGroup="switch"/>
<xs:complexType name="LanguageType">
<xs:group ref="Node"/>
<xs:attribute name="matches" type="xs:string" use="required">
<xs:annotation>
<xs:documentation>The value of one of these parameters is a
language-tag, as defined in RFC
3066.</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:anyAttribute namespace="##any" processContents="lax"/>
</xs:complexType>
<xs:complexType name="LanguageSwitchType">
<xs:complexContent>
<xs:extension base="SwitchType">
<xs:sequence>
<xs:element name="language" type="LanguageType"
minOccurs="0" maxOccurs="unbounded"/>
<xs:sequence minOccurs="0">
<xs:element name="not-present" type="NotPresentAction"/>
<xs:element name="language" type="LanguageType"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
<xs:element name="otherwise" type="OtherwiseAction"
minOccurs="0"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:element name="language-switch" type="LanguageSwitchType"
substitutionGroup="switch"/>
<xs:simpleType name="FreqType">
<xs:restriction base="xs:NMTOKEN">
<xs:pattern value="[s|S][e|E][c|C][o|O][n|N][d|D][l|L][y|Y]"/>
<xs:pattern value="[m|M][i|I][n|N][u|U][t|T][e|E][l|L][y|Y]"/>
<xs:pattern value="[h|H][o|O][u|U][r|R][l|L][y|Y]"/>
<xs:pattern value="[d|D][a|A][i|I][l|L][y|Y]"/>
<xs:pattern value="[w|W][e|E][e|E][k|K][l|L][y|Y]"/>
<xs:pattern value="[m|M][o|N][n|N][t|T][h|H][l|L][y|Y]"/>
<xs:pattern value="[y|Y][e|E][a|A][r|R][l|L][y|Y]"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType name="YearDayType">
<xs:union>
<xs:simpleType>
<xs:restriction base="xs:integer">
<xs:minInclusive value="-366"/>
<xs:maxInclusive value="-1"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType>
<xs:restriction base="xs:integer">
<xs:minInclusive value="1"/>
<xs:maxExclusive value="366"/>
</xs:restriction>
</xs:simpleType>
</xs:union>
</xs:simpleType>
<xs:simpleType name="DayType">
<xs:restriction base="xs:NMTOKEN">
<xs:pattern value="[m|M][o|O]"/>
<xs:pattern value="[t|T][u|U]"/>
<xs:pattern value="[w|W][e|E]"/>
<xs:pattern value="[t|T][h|H]"/>
<xs:pattern value="[f|F][r|R]"/>
<xs:pattern value="[s|S][a|A]"/>
<xs:pattern value="[s|S][u|U]"/>
</xs:restriction>
</xs:simpleType>
<xs:complexType name="TimeType">
<xs:annotation>
<xs:documentation>Exactly one of the two attributes "dtend" and
"duration" must occur. None of the attributes following
freq are meaningful unless freq appears.
</xs:documentation>
</xs:annotation>
<xs:group ref="Node"/>
<xs:attribute name="dtstart" type="xs:string" use="required">
<xs:annotation>
<xs:documentation>RFC 2445 DATE-TIME</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="dtend" type="xs:string" use="optional">
<xs:annotation>
<xs:documentation>RFC 2445 DATE-TIME</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="duration" type="xs:string" use="optional">
<xs:annotation>
<xs:documentation>RFC 2445 DURATION</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="freq" type="FreqType" use="optional"/>
<xs:attribute name="interval" type="xs:positiveInteger"
default="1"/>
<xs:attribute name="until" type="xs:string" use="optional">
<xs:annotation>
<xs:documentation>RFC 2445 DATE-TIME</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="count" type="xs:positiveInteger"
use="optional"/>
<xs:attribute name="bysecond" type="xs:string" use="optional">
<xs:annotation>
<xs:documentation>Comma-separated list of seconds within a
minute. Valid values are 0 to 59.</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="byminute" type="xs:string" use="optional">
<xs:annotation>
<xs:documentation>Comma-separated list of minutes within an
hour. Valid values are 0 to 59.</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="byhour" type="xs:string" use="optional">
<xs:annotation>
<xs:documentation>Comma-separated list of hours of the day.
Valid values are 0 to 23.</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="byday" type="xs:string" use="optional">
<xs:annotation>
<xs:documentation>Comma-separated list of days of the week.
Valid values are "MO", "TU", "WE", "TH", "FR", "SA" and
"SU". These values are not case-sensitive. Each can be
preceded by a positive (+n) or negative (-n)
integer.</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="bymonthday" type="xs:string" use="optional">
<xs:annotation>
<xs:documentation>Comma-separated list of days of the month.
Valid values are 1 to 31 or -31 to
-1.</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="byyearday" type="xs:string" use="optional">
<xs:annotation>
<xs:documentation>Comma-separated list of days of the year.
Valid values are 1 to 366 or -366 to
-1.</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="byweekno" type="xs:string" use="optional">
<xs:annotation>
<xs:documentation>Comma-separated list of ordinals specifying
weeks of the year. Valid values are 1 to 53 or -53 to
-1.</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="bymonth" type="xs:string" use="optional">
<xs:annotation>
<xs:documentation>Comma-separated list of months of the year.
Valid values are 1 to 12.</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="wkst" type="DayType" default="MO"/>
<xs:attribute name="bysetpos" type="YearDayType"/>
<xs:anyAttribute namespace="##any" processContents="lax"/>
</xs:complexType>
<xs:simpleType name="TZIDType">
<xs:restriction base="xs:string"/>
</xs:simpleType>
<xs:simpleType name="TZURLType">
<xs:restriction base="xs:anyURI"/>
</xs:simpleType>
<xs:complexType name="TimeSwitchType">
<xs:complexContent>
<xs:extension base="SwitchType">
<xs:sequence>
<xs:element name="time" type="TimeType" minOccurs="0"
maxOccurs="unbounded"/>
<xs:sequence minOccurs="0">
<xs:element name="not-present" type="NotPresentAction"/>
<xs:element name="time" type="TimeType" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
<xs:element name="otherwise" type="OtherwiseAction"
minOccurs="0"/>
</xs:sequence>
<xs:attribute name="tzid" type="TZIDType"/>
<xs:attribute name="tzurl" type="TZURLType"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:element name="time-switch" type="TimeSwitchType"
substitutionGroup="switch"/>
<xs:simpleType name="PriorityValues">
<xs:restriction base="xs:NMTOKEN">
<xs:pattern
value="[e|E][m|M][e|E][r|R][g|G][e|E][n|N][c|C][y|Y]"/>
<xs:pattern value="[u|U][r|R][g|G][e|E][n|N][t|T]"/>
<xs:pattern value="[n|N][o|O][r|R][m|M][a|A][l|L]"/>
<xs:pattern
value="[n|N][o|O][n|N]-[u|U][r|R][g|G][e|E][n|N][t|T]"/>
</xs:restriction>
</xs:simpleType>
<xs:complexType name="PriorityType">
<xs:annotation>
<xs:documentation>Exactly one of the three attributes must
appear </xs:documentation>
</xs:annotation>
<xs:group ref="Node"/>
<xs:attribute name="less" type="PriorityValues"/>
<xs:attribute name="greater" type="PriorityValues"/>
<xs:attribute name="equal" type="xs:string">
<xs:annotation>
<xs:documentation>case-insensitive</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:anyAttribute namespace="##any" processContents="lax"/>
</xs:complexType>
<xs:complexType name="PrioritySwitchType">
<xs:complexContent>
<xs:extension base="SwitchType">
<xs:sequence>
<xs:element name="priority" type="PriorityType"
minOccurs="0" maxOccurs="unbounded"/>
<xs:sequence minOccurs="0">
<xs:element name="not-present" type="NotPresentAction"/>
<xs:element name="priority" type="PriorityType"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
<xs:element name="otherwise" type="OtherwiseAction"
minOccurs="0"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:element name="priority-switch" type="PrioritySwitchType"
substitutionGroup="switch"/>
<xs:simpleType name="LocationPriorityType">
<xs:restriction base="xs:float">
<xs:minInclusive value="0.0"/>
<xs:maxInclusive value="1.0"/>
</xs:restriction>
</xs:simpleType>
<xs:complexType name="LocationType">
<xs:complexContent>
<xs:extension base="ModifierType">
<xs:group ref="Node"/>
<xs:attribute name="url" type="xs:anyURI" use="required"/>
<xs:attribute name="priority" type="LocationPriorityType"
use="optional" default="1.0"/>
<xs:attribute name="clear" type="YesNoType" default="no"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:complexType name="LookupType">
<xs:complexContent>
<xs:extension base="ModifierType">
<xs:all>
<xs:element name="success" minOccurs="0">
<xs:complexType>
<xs:group ref="Node"/>
</xs:complexType>
</xs:element>
<xs:element name="notfound" minOccurs="0">
<xs:complexType>
<xs:group ref="Node"/>
</xs:complexType>
</xs:element>
<xs:element name="failure" minOccurs="0">
<xs:complexType>
<xs:group ref="Node"/>
</xs:complexType>
</xs:element>
</xs:all>
<xs:attribute name="source" type="xs:string"
use="required"/>
<xs:attribute name="timeout" type="xs:positiveInteger"
default="30"/>
<xs:attribute name="clear" type="YesNoType" default="no"/>
</xs:extension>
</xs:complexContent>