This is WSO2 GREG RXT file for book schema

book_rxt.xml

<?xml version="1.0"?>
<artifactType hasNamespace="true" iconSet="9" pluralLabel="MyBookLibrary" shortName="mybooklibrary"
singularLabel="MyBookLibrary" type="application/vnd.wso2-mmbrepo+xml">
        <storagePath>/MyBookLibrary/@{details_name}</storagePath>
        <nameAttribute>details_name</nameAttribute>
        <namespaceAttribute>details_namespace</namespaceAttribute>
        <lifecycle>BookServiceLifeCycle</lifecycle>
        <ui>
            <list>
                <column name="Name">
                    <data href="@{storagePath}" type="path" value="details_name"/>
                </column>
                <column name="Description">
                    <data href="@{storagePath}" type="path" value="rules_description"/>
                </column>
            </list>
        </ui>
        <content>
            <table name="Details">
                <field required="true" type="text">
                    <name>Name</name>
                </field>
                <field required="true" type="text">
                    <name>Author</name>
                </field>
                <field required="true" type="text">
                    <name>Publisher</name>
                </field>
                <field required="true" type="text">
                    <name>ISBN</name>
                </field>
                <field required="true" type="text">
                    <name>URL</name>
                </field>
            </table>
            <table name="BookFormat">
                <field type="options">
                    <name>BookFormat</name>
                    <values>
                        <value>AudiobookFormat</value>
                        <value>Ebook</value>
                        <value>HardCover</value>
                        <value>Paperback</value>
                    </values>
                </field>
                <field type="text-area">
                    <name>Description</name>
                </field>
                <field type="text">
                    <name>Availability</name>
                </field>
            </table>
            <table name="Publishers">
                <subheading>
                    <heading>Country</heading><heading>Publisher</heading>
                </subheading>
                <field maxoccurs="unbounded" type="option-text">
                    <name label="Contact">Contact</name>
                    <values>
                        <value>UK</value><value>US</value><value>SL</value>
                    </values>
                </field>
            </table>
            <table name="Service Lifecycle">
                <field type="options">
                    <name label="Lifecycle Name">Lifecycle Name</name>
                    <values class="org.wso2.carbon.governance.services.ui.utils.LifecycleListPopulator">
                </values></field>
            </table>
            <table name="Contacts">
            <subheading>
                <heading>Contact Type</heading>
                <heading>Contact Name/Organization Name/Email Address</heading>
            </subheading>
            <field type="option-text" maxoccurs="unbounded">
                <name label="Contact">Contact</name>
                <values>
                    <value>None</value>
                    <value>Technical Owner</value>
                    <value>Technical Owner Email</value>
                    <value>Business Owner</value>
                    <value>Business Owner Email</value>
                </values>
            </field>
        </table>
        <table name="NumberOfPages">
            <field type="options">
                <name label="Page Count">Page Count</name>
                <values>
                    <value>Less than 10 pages</value>
                    <value>Between 100 and 1,000</value>
                    <value>Between 1,000 and 10,000</value>
                    <value>Between 10,000 and 25,000</value>
                    <value>More than 25,000 pages</value>
                </values>
            </field>
        </table>
        </content>
    </artifactType>