Light edits

docs/guide/rest-rate-limiting.md

@@ -1,28 +1,28 @@
 Rate Limiting
 =============
 
-To prevent abuse, you should consider adding rate limiting to your APIs. For example, you may limit the API usage
+To prevent abuse, you should consider adding *rate limiting* to your APIs. For example, you may want to limit the API usage
 of each user to be at most 100 API calls within a period of 10 minutes. If too many requests are received from a user
-within the period of the time, a response with status code 429 (meaning Too Many Requests) should be returned.
+within the stated period of the time, a response with status code 429 (meaning "Too Many Requests") should be returned.
 
 To enable rate limiting, the [[yii\web\User::identityClass|user identity class]] should implement [[yii\filters\RateLimitInterface]].
-This interface requires implementation of the following three methods:
+This interface requires implementation of three methods:
 
-* `getRateLimit()`: returns the maximum number of allowed requests and the time period, e.g., `[100, 600]` means
-  at most 100 API calls within 600 seconds.
+* `getRateLimit()`: returns the maximum number of allowed requests and the time period (e.g., `[100, 600]` means there can be at most 100 API calls within 600 seconds).
 * `loadAllowance()`: returns the number of remaining requests allowed and the corresponding UNIX timestamp
-  when the rate limit is checked last time.
-* `saveAllowance()`: saves the number of remaining requests allowed and the current UNIX timestamp.
+  when the rate limit was last checked.
+* `saveAllowance()`: saves both the number of remaining requests allowed and the current UNIX timestamp.
 
-You may use two columns in the user table to record the allowance and timestamp information.
-And `loadAllowance()` and `saveAllowance()` can then be implementation by reading and saving the values
+You may want to use two columns in the user table to record the allowance and timestamp information. With those defined, then `loadAllowance()` and `saveAllowance()` can be implemented to read and save the values
 of the two columns corresponding to the current authenticated user. To improve performance, you may also
-consider storing these information in cache or some NoSQL storage.
+consider storing these pieces of information in a cache or NoSQL storage.
 
 Once the identity class implements the required interface, Yii will automatically use [[yii\filters\RateLimiter]]
 configured as an action filter for [[yii\rest\Controller]] to perform rate limiting check. The rate limiter
-will thrown a [[yii\web\TooManyRequestsHttpException]] if rate limit is exceeded. You may configure the rate limiter
-as follows in your REST controller classes,
+will throw a [[yii\web\TooManyRequestsHttpException]] when the rate limit is exceeded. 
+
+You may configure the rate limiter
+as follows in your REST controller classes:
 
 ```php
 public function behaviors()
@@ -36,9 +36,9 @@ public function behaviors()
 When rate limiting is enabled, by default every response will be sent with the following HTTP headers containing
 the current rate limiting information:
 
-* `X-Rate-Limit-Limit`: The maximum number of requests allowed with a time period;
-* `X-Rate-Limit-Remaining`: The number of remaining requests in the current time period;
-* `X-Rate-Limit-Reset`: The number of seconds to wait in order to get the maximum number of allowed requests.
+* `X-Rate-Limit-Limit`, the maximum number of requests allowed with a time period
+* `X-Rate-Limit-Remaining`, the number of remaining requests in the current time period
+* `X-Rate-Limit-Reset`, the number of seconds to wait in order to get the maximum number of allowed requests
 
 You may disable these headers by configuring [[yii\filters\RateLimiter::enableRateLimitHeaders]] to be false,
-like shown in the above code example.
+as shown in the above code example.