Change 'a HTTP' to 'an HTTP' [ci skip]

3 files changed, 5 insertions, 5 deletions

diff --git a/guides/source/layouts_and_rendering.md b/guides/source/layouts_and_rendering.md
index 83173e8d75..614ca4dbe1 100644
--- a/guides/source/layouts_and_rendering.md
+++ b/guides/source/layouts_and_rendering.md
@@ -700,7 +700,7 @@ This would detect that there are no books with the specified ID, populate the `@
 
 ### Using `head` To Build Header-Only Responses
 
-The `head` method can be used to send responses with only headers to the browser. The `head` method accepts a number or symbol (see [reference table](#the-status-option)) representing a HTTP status code. The options argument is interpreted as a hash of header names and values. For example, you can return only an error header:
+The `head` method can be used to send responses with only headers to the browser. The `head` method accepts a number or symbol (see [reference table](#the-status-option)) representing an HTTP status code. The options argument is interpreted as a hash of header names and values. For example, you can return only an error header:
 
 ```ruby
 head :bad_request
diff --git a/guides/source/security.md b/guides/source/security.md
index 98324141cc..f4a9f64669 100644
--- a/guides/source/security.md
+++ b/guides/source/security.md
@@ -381,7 +381,7 @@ Refer to the Injection section for countermeasures against XSS. It is _recommend
 
 **CSRF** Cross-Site Request Forgery (CSRF), also known as Cross-Site Reference Forgery (XSRF), is a gigantic attack method, it allows the attacker to do everything the administrator or Intranet user may do. As you have already seen above how CSRF works, here are a few examples of what attackers can do in the Intranet or admin interface.
 
-A real-world example is a [router reconfiguration by CSRF](http://www.h-online.com/security/news/item/Symantec-reports-first-active-attack-on-a-DSL-router-735883.html). The attackers sent a malicious e-mail, with CSRF in it, to Mexican users. The e-mail claimed there was an e-card waiting for the user, but it also contained an image tag that resulted in a HTTP-GET request to reconfigure the user's router (which is a popular model in Mexico). The request changed the DNS-settings so that requests to a Mexico-based banking site would be mapped to the attacker's site. Everyone who accessed the banking site through that router saw the attacker's fake web site and had their credentials stolen.
+A real-world example is a [router reconfiguration by CSRF](http://www.h-online.com/security/news/item/Symantec-reports-first-active-attack-on-a-DSL-router-735883.html). The attackers sent a malicious e-mail, with CSRF in it, to Mexican users. The e-mail claimed there was an e-card waiting for the user, but it also contained an image tag that resulted in an HTTP-GET request to reconfigure the user's router (which is a popular model in Mexico). The request changed the DNS-settings so that requests to a Mexico-based banking site would be mapped to the attacker's site. Everyone who accessed the banking site through that router saw the attacker's fake web site and had their credentials stolen.
 
 Another example changed Google Adsense's e-mail address and password. If the victim was logged into Google Adsense, the administration interface for Google advertisement campaigns, an attacker could change the credentials of the victim.

 
@@ -453,7 +453,7 @@ However, the attacker may also take over the account by changing the e-mail addr
 
 #### Other
 
-Depending on your web application, there may be more ways to hijack the user's account. In many cases CSRF and XSS will help to do so. For example, as in a CSRF vulnerability in [Google Mail](http://www.gnucitizen.org/blog/google-gmail-e-mail-hijack-technique/). In this proof-of-concept attack, the victim would have been lured to a web site controlled by the attacker. On that site is a crafted IMG-tag which results in a HTTP GET request that changes the filter settings of Google Mail. If the victim was logged in to Google Mail, the attacker would change the filters to forward all e-mails to their e-mail address. This is nearly as harmful as hijacking the entire account. As a countermeasure, _review your application logic and eliminate all XSS and CSRF vulnerabilities_.
+Depending on your web application, there may be more ways to hijack the user's account. In many cases CSRF and XSS will help to do so. For example, as in a CSRF vulnerability in [Google Mail](http://www.gnucitizen.org/blog/google-gmail-e-mail-hijack-technique/). In this proof-of-concept attack, the victim would have been lured to a web site controlled by the attacker. On that site is a crafted IMG-tag which results in an HTTP GET request that changes the filter settings of Google Mail. If the victim was logged in to Google Mail, the attacker would change the filters to forward all e-mails to their e-mail address. This is nearly as harmful as hijacking the entire account. As a countermeasure, _review your application logic and eliminate all XSS and CSRF vulnerabilities_.
 
 ### CAPTCHAs
 
@@ -466,7 +466,7 @@ The problem with CAPTCHAs is that they have a negative impact on the user experi
 
 Most bots are really dumb. They crawl the web and put their spam into every form's field they can find. Negative CAPTCHAs take advantage of that and include a "honeypot" field in the form which will be hidden from the human user by CSS or JavaScript.
 
-Note that negative CAPTCHAs are only effective against dumb bots and won't suffice to protect critical applications from targeted bots. Still, the negative and positive CAPTCHAs can be combined to increase the performance, e.g.,  if the "honeypot" field is not empty (bot detected), you won't need to verify the positive CAPTCHA, which would require a HTTPS request to Google ReCaptcha before computing the response.
+Note that negative CAPTCHAs are only effective against dumb bots and won't suffice to protect critical applications from targeted bots. Still, the negative and positive CAPTCHAs can be combined to increase the performance, e.g.,  if the "honeypot" field is not empty (bot detected), you won't need to verify the positive CAPTCHA, which would require an HTTPS request to Google ReCaptcha before computing the response.
 
 Here are some ideas how to hide honeypot fields by JavaScript and/or CSS:
 
diff --git a/guides/source/testing.md b/guides/source/testing.md
index 09eec7a64c..e302611b2a 100644
--- a/guides/source/testing.md
+++ b/guides/source/testing.md
@@ -798,7 +798,7 @@ and
 can be set directly on the `@request` instance variable:
 
 ```ruby
-# setting a HTTP Header
+# setting an HTTP Header
 @request.headers["Accept"] = "text/plain, text/html"
 get articles_url # simulate the request with custom header