anchor.diff:  *Generic Webhooks*
   
   Generic webhooks can be invoked from any system capable of making a web
  -request. As with a GitHub webhook, you must specify a `*secret*` when defining the
  -trigger, and the caller must provide this `*secret*` to trigger the build. The
  -following is an example trigger definition JSON within the `*BuildConfig*`:
  +request. As with a GitHub webhook, you must specify a `*secret*` which will be
  +part of the URL, the caller must use to trigger the build. The secret ensures
  +the uniqueness of the URL, preventing others from triggering the build.
  +The following is an example trigger definition JSON within the `*BuildConfig*`:
   
   ====
   
  
positive.code: 
  https://developer.github.com/webhooks/creating/[GitHub webhooks] handle the call
  made by GitHub when a repository is updated. When defining the trigger, you must
  specify a link:../dev_guide/secrets.html[`*secret*`] as part of the URL you supply
  to GitHub when configuring the webhook. The `*secret*` ensures that only you and
  your repository can trigger the build. The following example is a trigger
  definition JSON within the `*BuildConfig*`:
  
  ====
  
  
negative.code: ----
  ====
  
  [NOTE]
  ====
  The secret field in webhook trigger configuration is not the same as `*secret*`
  field you encounter when configuring webhook in GitHub UI. The former is to make
  the webhook URL unique and hard to predict, the latter is an optional string field
  used to create HMAC hex digest of the body, which is sent as an `X-Hub-Signature`
  https://developer.github.com/webhooks/#delivery-headers[header].
  ====
  
  The payload URL is returned as the GitHub Webhook URL by the `describe` command
  (see link:#describe-buildconfig[below]), and is structured as follows:
  
  