<?= $form->field($model, 'jc')->textInput()->lable('城市简称 可自行修改') ?>

model文件里有如下方法：

public function attributeLabels()
    {
        return [
            '字段名' => Yii::t('app', '城市简称可自行修改'),
        ];
    }

public function attributeLabels()
{
    return [
        'id' => 'ID',
        'name' => '城市名称',
        'prefix' => '城市简称',
        'pinyin' => '城市拼音',
        'domain' => '站点链接', 
    ];
}


public function attributeLabels()
{
    return [
        'prefix' => Yii::t('app', '城市简称可自行修改！'),
    ];
}

可以參照 @jackiegao 的方法或者參考以下

<?= $form->field($model, 'city_abbreviation', [
    'template' => "
        {label}<span style='padding-left:10px;'>城市简称可自行修改！</span>\n{input}\n{hint}\n{error}"
    ]
)?>

<?= $form->field($model, 'jc')->textInput()->lable('城市简称 可自行修改') ?>

rules() public method
[
    // built-in "required" validator
    [['username', 'password'], 'required'],
    // built-in "string" validator customized with "min" and "max" properties
    ['username', 'string', 'min' => 3, 'max' => 12],
    // built-in "compare" validator that is used in "register" scenario only
    ['password', 'compare', 'compareAttribute' => 'password2', 'on' => 'register'],
    // an inline validator defined via the "authenticate()" method in the model class
    ['password', 'authenticate', 'on' => 'login'],
    // a validator of class "DateRangeValidator"
    ['dateRange', 'DateRangeValidator'],
];
<a href="http://www.yiichina.com/doc/api/2.0/yii-base-model#rules()-detail">点击访问链接，可能是你想要的！</a>