需求：
一、标题：打开template/default/common/header_common.htm文件，里面的代码如下
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset={CHARSET}" />
<!--{if $_G['config']['output']['iecompatible']}--><meta http-equiv="X-UA-Compatible" content="IE=EmulateIE{$_G['config']['output']['iecompatible']}" /><!--{/if}-->
<title><!--{if !empty($navtitle)}-->$navtitle - <!--{/if}--><!--{if empty($nobbname)}--> $_G['setting']['bbname']<!--{/if}-->Powered by Discuz!</title>
$_G['setting']['seohead']
<meta name="keywords" content="{if !empty($metakeywords)}{echo dhtmlspecialchars($metakeywords)}{/if}" />
<meta name="description" content="{if !empty($metadescription)}{echo dhtmlspecialchars($metadescription)} {/if}{if empty($nobbname)},$_G['setting']['bbname']{/if}" />
<meta name="generator" content="Discuz! $_G['setting']['version']" />
<meta name="author" content="Discuz! Team and Comsenz UI Team" />
<meta name="copyright" content="2001-2017 Comsenz Inc." />
<meta name="MSSmartTagsPreventParsing" content="True" />
<meta http-equiv="MSThemeCompatible" content="Yes" />
<base href="{$_G['siteurl']}" rel="external nofollow" />
<!--{csstemplate}-->
<script type="text/javascript">var STYLEID = '{STYLEID}', STATICURL = '{STATICURL}', IMGDIR = '{IMGDIR}', VERHASH = '{VERHASH}', charset = '{CHARSET}', discuz_uid = '$_G[uid]', cookiepre = '{$_G[config][cookie][cookiepre]}', cookiedomain = '{$_G[config][cookie][cookiedomain]}', cookiepath = '{$_G[config][cookie][cookiepath]}', showusercard = '{$_G[setting][showusercard]}', attackevasive = '{$_G[config][security][attackevasive]}', disallowfloat = '{$_G[setting][disallowfloat]}', creditnotice = '<!--{if $_G['setting']['creditnotice']}-->$_G['setting']['creditnames']<!--{/if}-->', defaultstyle = '$_G[style][defaultextstyle]', REPORTURL = '$_G[currenturl_encode]', SITEURL = '$_G[siteurl]', JSPATH = '$_G[setting][jspath]', CSSPATH = '$_G[setting][csspath]', DYNAMICURL = '$_G[dynamicurl]';</script>
<script type="text/javascript" src="{$_G[setting][jspath]}common.js?{VERHASH}"></script>
<!--{if empty($_GET['diy'])}--><!--{eval $_GET['diy'] = '';}--><!--{/if}-->
<!--{if !isset($topic)}--><!--{eval $topic = array();}--><!--{/if}-->
1、原来的标题代码为：
<title><!--{if !empty($navtitle)}-->$navtitle - <!--{/if}--><!--{if empty($nobbname)}--> $_G['setting']['bbname']<!--{/if}-->Powered by Discuz!</title>
修改为：
<title><!--{if !empty($navtitle)}-->$navtitle<!--{/if}--><!--{if empty($nobbname)}--> $_G['setting']['bbname'] <!--{/if}--></title>
注意：一定记着把$navtitle后面的“ - ”去掉，要不然标题处还是会出现 - ，例如下图：
2、原来的描述代码为：
<meta name="description" content="{if !empty($metadescription)}{echo dhtmlspecialchars($metadescription)} {/if}{if empty($nobbname)},$_G['setting']['bbname']{/if}" />
修改为：
<meta name="description" content="{if !empty($metadescription)}{echo dhtmlspecialchars($metadescription)} {/if}" />
二、底部：找到底部的模板文件template/default/common/footer.htm或者你模板文件对应的common/footer.htm，搜索“Powered by”，找到相关代码行删掉即可
<div id="frt">
<p>Powered by <strong><a href="http://www.discuz.net" rel="external nofollow" target="_blank">Discuz!</a></strong> <em>$_G['setting']['version']</em><!--{if !empty($_G['setting']['boardlicensed'])}--> <a href="http://license.comsenz.com/?pid=1&host=$_SERVER[HTTP_HOST]" rel="external nofollow" target="_blank">Licensed</a><!--{/if}--></p>
<p class="xs0">© 2001-2017 <a href="http://www.comsenz.com" rel="external nofollow" target="_blank">Comsenz Inc.</a></p>
</div>
三、修改完成后，登录后台更新一下缓存即可，最终效果如下图，是不是非常完美。
