默认编辑器内容pu_default_editor_content() 当用户禁用可视化编辑器时（根据您的注释），将考虑该函数。

function pu_default_editor_content( $content ) {
    global $post_type;

    switch( $post_type ) {
        case \'post\' :
            $content = \'Default content for blog posts. » » »\';
            $rich_editing = get_user_option( \'rich_editing\', get_current_user_id() );

            if ( \'false\' === $rich_editing ) {
                $content = htmlspecialchars( $content );
            }   
        break;
    }

    return $content;
}
add_filter( \'default_content\', \'pu_default_editor_content\' );

富文本编辑器禁用视图

TinyMCE/QuickTags如果启用了可视化编辑器（这是默认设置），则需要将TinyMCE配置为显示命名实体。TinyMCE正在应用编码，但可以通过tiny_mce_before_init 钩Thanks to this answer 给小费。

将可能需要的其他实体添加到$settings[\'entities\'] 一串有关格式的文档是here:

此选项包含一个逗号分隔的实体名称列表，该列表用于代替字符。奇数项是字符代码，偶数项是字符代码的名称。

// Custom configuration for TinyMCE
function wpse241282_tiny_mce_before_init( $settings, $editor_id ) {

    // Used named encodings (the default setting in WordPress is raw).
    // https://www.tinymce.com/docs/configure/content-filtering/#encodingtypes
    $settings[\'entity_encoding\'] = \'named\';

    // Default entities for TinyMCE: 38,amp,60,lt,62,gt1
    // Additional entities: copy, reg, trade, service mark, euro, right angle quote, left angle quote
    // The odd entires are the entity *number*, the even entries are the entity *name*. If the entity has no name,
    // use the number, prefixed with a hash (for example, the service mark is "8480,#8480").

    $entities = \'169,copy,174,reg,8482,trade,8480,#8480,8364,euro,187,raquo,171,laquo\';

    if ( isset( $settings[\'entities\'] ) && ! empty( $settings[\'entities\'] ) ) {
        $settings[\'entities\'] .= \',\' . $entities;
    } else {
        $settings[\'entities\'] = $entities;
    }
    return $settings;
}
add_filter( \'tiny_mce_before_init\', \'wpse241282_tiny_mce_before_init\', 10, 2 );
add_filter( \'quicktags_settings\', \'wpse241282_tiny_mce_before_init\', 10, 2 );

已启用可视化编辑器