如何修复设置xml中无法识别的标签？

<settings
        xmlns="http://maven.apache.org/SETTINGS/1.0.0"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0 http://maven.apache.org/xsd/settings-1.0.0.xsd">
    <mirrors>
        <mirror>
            <id>Nexus.Codehaus Snapshots</id>
            <name>Nexus Mirror of Codehaus Snapshots</name>
            <url>http://build/nexus/content/repositories/codehaus-snapshots</url>
            <mirrorOf>Codehaus Snapshots</mirrorOf>
        </mirror>
        <mirror>
            <id>Nexus</id>
            <name>Nexus Public Mirror</name>
            <url>http://nexus.other.com/content/groups/public</url>
            <mirrorOf>Nexus</mirrorOf>
        </mirror>
    </mirrors>

    <server>
        <id>TomcatServer</id>
        <username>admin</username>
        <password>password</password>
    </server>

    <profiles>
        <profile>
            <id>quickBuild</id>
            <activation>
                <activeByDefault>false</activeByDefault>
            </activation>
            <properties>
                <maven.test.skip>true</maven.test.skip>
                <pmd.skip>true</pmd.skip>
                <checkstyle.skip>true</checkstyle.skip>
                <findbugs.skip>true</findbugs.skip>
            </properties>
            <build>
                <plugins>
                    <plugin>
                        <groupId>org.apache.maven.plugins</groupId>
                        <artifactId>maven-compiler-plugin</artifactId>
                        <configuration>
                            <source>${java.version}</source>
                            <target>${java.version}</target>
                            <debug>true</debug>
                            <debuglevel>lines,vars,source</debuglevel>
                        </configuration>
                    </plugin>
                    <plugin>
                        <groupId>org.apache.maven.plugins</groupId>
                        <artifactId>maven-javadoc-plugin</artifactId>
                        <executions>
                            <execution>
                                <id>some</id>
                                <phase>none</phase>
                            </execution>
                        </executions>
                    </plugin>
                    <plugin>
                        <groupId>org.codehaus.mojo</groupId>
                        <artifactId>findbugs-maven-plugin</artifactId>
                        <executions>
                            <execution>
                                <id>some2</id>
                                <phase>none</phase>
                            </execution>
                        </executions>
                    </plugin>
                    <plugin>
                        <groupId>org.apache.maven.plugins</groupId>
                        <artifactId>maven-pmd-plugin</artifactId>
                        <executions>
                            <execution>
                                <id>some3</id>
                                <phase>none</phase>
                            </execution>
                        </executions>
                    </plugin>
                    <plugin>
                        <groupId>org.apache.maven.plugins</groupId>
                        <artifactId>maven-checkstyle-plugin</artifactId>
                        <executions>
                            <execution>
                                <id>some4</id>
                                <phase>none</phase>
                            </execution>
                        </executions>
                    </plugin>
                    <plugin>
                        <groupId>org.codehaus.mojo</groupId>
                        <artifactId>jaxws-maven-plugin</artifactId>
                        <executions>
                            <execution>
                                <id>some5</id>
                                <phase>none</phase>
                            </execution>
                        </executions>
                    </plugin>
                </plugins>
            </build>
        </profile>
        <profile>
            <id>repository-profile</id>
            <activation>
                <activeByDefault>false</activeByDefault>
            </activation>
            <repositories>
                <repository>
                    <id>maven2-repository.dev.java.net</id>
                    <name>Java.net Repository for Maven</name>
                    <url>http://download.java.net/maven/2/</url>
                    <layout>default</layout>
                </repository>
            </repositories>
        </profile>
    </profiles>
</settings>

在maven构建开始时,我有一条消息：

[WARNING] 
[WARNING] Some problems were encountered while building the effective settings
[WARNING] Unrecognised tag: 'server' (position: START_TAG seen ...</mirrors>rntrnt<server>... @31:10)  @ D:directory.m2settings.xml,line 31,column 10
[WARNING]

我不明白为什么？据我所知,服务器标签和镜像是有效的(我认为是因为插件和依赖解析工作).我怎么解决这个问题？