use id instead of name for anchor references in the guide

fixes #7013

docs/guide/input-validation.md

@@ -23,7 +23,7 @@ if ($model->validate()) {
 ```
 
 
-## Declaring Rules <a name="declaring-rules"></a>
+## Declaring Rules <span id="declaring-rules"></span>
 
 To make `validate()` really work, you should declare validation rules for the attributes you plan to validate.
 This should be done by overriding the [[yii\base\Model::rules()]] method. The following example shows how
@@ -95,7 +95,7 @@ an active attribute declared in `scenarios()` and is associated with one or mult
 declared in `rules()`.
 
 
-### Customizing Error Messages <a name="customizing-error-messages"></a>
+### Customizing Error Messages <span id="customizing-error-messages"></span>
 
 Most validators have default error messages that will be added to the model being validated when its attributes
 fail the validation. For example, the [[yii\validators\RequiredValidator|required]] validator will add
@@ -120,7 +120,7 @@ to describe the validation failure when the value being validated is too big and
 You may configure these error messages like configuring other properties of validators in a validation rule.
 
 
-### Validation Events <a name="validation-events"></a>
+### Validation Events <span id="validation-events"></span>
 
 When [[yii\base\Model::validate()]] is called, it will call two methods that you may override to customize
 the validation process:
@@ -134,7 +134,7 @@ the validation process:
   the validation is completed.
 
 
-### Conditional Validation <a name="conditional-validation"></a>
+### Conditional Validation <span id="conditional-validation"></span>
 
 To validate attributes only when certain conditions apply, e.g. the validation of one attribute depends
 on the value of another attribute you can use the [[yii\validators\Validator::when|when]] property
@@ -174,7 +174,7 @@ function whose return value determines whether to apply the rule or not. For exa
 ```
 
 
-### Data Filtering <a name="data-filtering"></a>
+### Data Filtering <span id="data-filtering"></span>
 
 User inputs often need to be filtered or preprocessed. For example, you may want to trim the spaces around the
 `username` input. You may use validation rules to achieve this goal.
@@ -196,7 +196,7 @@ As you can see, these validation rules do not really validate the inputs. Instea
 and save them back to the attributes being validated.
 
 
-### Handling Empty Inputs <a name="handling-empty-inputs"></a>
+### Handling Empty Inputs <span id="handling-empty-inputs"></span>
 
 When input data are submitted from HTML forms, you often need to assign some default values to the inputs
 if they are empty. You can do so by using the [default](tutorial-core-validators.md#default) validator. For example,
@@ -229,7 +229,7 @@ with a PHP callable. For example,
   `required`, and `trim` validators will handle empty inputs.
 
 
-## Ad Hoc Validation <a name="ad-hoc-validation"></a>
+## Ad Hoc Validation <span id="ad-hoc-validation"></span>
 
 Sometimes you need to do *ad hoc validation* for values that are not bound to any model.
 
@@ -298,13 +298,13 @@ You may also access the dynamic attributes defined through the model instance, e
 `$model->name` and `$model->email`.
 
 
-## Creating Validators <a name="creating-validators"></a>
+## Creating Validators <span id="creating-validators"></span>
 
 Besides using the [core validators](tutorial-core-validators.md) included in the Yii releases, you may also
 create your own validators. You may create inline validators or standalone validators.
 
 
-### Inline Validators <a name="inline-validators"></a>
+### Inline Validators <span id="inline-validators"></span>
 
 An inline validator is one defined in terms of a model method or an anonymous function. The signature of
 the method/function is:
@@ -366,7 +366,7 @@ class MyForm extends Model
 > ```
 
 
-### Standalone Validators <a name="standalone-validators"></a>
+### Standalone Validators <span id="standalone-validators"></span>
 
 A standalone validator is a class extending [[yii\validators\Validator]] or its child class. You may implement
 its validation logic by overriding the [[yii\validators\Validator::validateAttribute()]] method. If an attribute
@@ -395,7 +395,7 @@ instead of `validateAttribute()` and `validate()` because by default the latter
 by calling `validateValue()`.
 
 
-## Client-Side Validation <a name="client-side-validation"></a>
+## Client-Side Validation <span id="client-side-validation"></span>
 
 Client-side validation based on JavaScript is desirable when end users provide inputs via HTML forms, because
 it allows users to find out input errors faster and thus provides a better user experience. You may use or implement
@@ -407,7 +407,7 @@ a validator that supports client-side validation *in addition to* server-side va
   described in the previous subsections.
 
 
-### Using Client-Side Validation <a name="using-client-side-validation"></a>
+### Using Client-Side Validation <span id="using-client-side-validation"></span>
 
 Many [core validators](tutorial-core-validators.md) support client-side validation out-of-the-box. All you need to do
 is just use [[yii\widgets\ActiveForm]] to build your HTML forms. For example, `LoginForm` below declares two
@@ -470,7 +470,7 @@ validation of individual input fields by configuring their [[yii\widgets\ActiveF
 property to be false.
 
 
-### Implementing Client-Side Validation <a name="implementing-client-side-validation"></a>
+### Implementing Client-Side Validation <span id="implementing-client-side-validation"></span>
 
 To create a validator that supports client-side validation, you should implement the
 [[yii\validators\Validator::clientValidateAttribute()]] method which returns a piece of JavaScript code
@@ -530,7 +530,7 @@ JS;
 > ]
 > ```
 
-### Deferred Validation <a name="deferred-validation"></a>
+### Deferred Validation <span id="deferred-validation"></span>
 
 If you need to perform asynchronous client-side validation, you can create [Deferred objects](http://api.jquery.com/category/deferred-object/).
 For example, to perform a custom AJAX validation, you can use the following code:
@@ -606,7 +606,7 @@ JS;
 ```
 
 
-### AJAX Validation <a name="ajax-validation"></a>
+### AJAX Validation <span id="ajax-validation"></span>
 
 Some validations can only be done on the server side, because only the server has the necessary information.
 For example, to validate if a username is unique or not, it is necessary to check the user table on the server side.