diff --git a/docs/sources/reference/commandline/cli.md b/docs/sources/reference/commandline/cli.md
index c0c7e9ee58..aef60d9dca 100644
--- a/docs/sources/reference/commandline/cli.md
+++ b/docs/sources/reference/commandline/cli.md
@@ -652,13 +652,36 @@ an [*ADD*](/reference/builder/#add) instruction to reference a file in the
 context.
 
 The `URL` parameter can specify the location of a Git repository;
-the repository acts as the build context.  The system recursively clones the repository
+the repository acts as the build context. The system recursively clones the repository
 and its submodules using a `git clone --depth 1 --recursive` command.
 This command runs in a temporary directory on your local host.
 After the command succeeds, the directory is sent to the Docker daemon as the context.
 Local clones give you the ability to access private repositories using
 local user credentials, VPN's, and so forth.
 
+Git URLs accept context configuration in their fragment section, separated by a colon `:`.
+The first part represents the reference that Git will check out, this can be either
+a branch, a tag, or a commit SHA. The second part represents a subdirectory
+inside the repository that will be used as a build context.
+
+For example, run this command to use a directory called `docker` in the branch `container`:
+
+      $ docker build https://github.com/docker/rootfs.git#container:docker
+
+The following table represents all the valid suffixes with their build contexts:
+
+Build Syntax Suffix | Commit Used | Build Context Used
+--------------------|-------------|-------------------
+`myrepo.git` | `refs/heads/master` | `/`
+`myrepo.git#mytag` | `refs/tags/mytag` | `/`
+`myrepo.git#mybranch` | `refs/heads/mybranch` | `/`
+`myrepo.git#abcdef` | `sha1 = abcdef` | `/`
+`myrepo.git#:myfolder` | `refs/heads/master` | `/myfolder`
+`myrepo.git#master:myfolder` | `refs/heads/master` | `/myfolder`
+`myrepo.git#mytag:myfolder` | `refs/tags/mytag` | `/myfolder`
+`myrepo.git#mybranch:myfolder` | `refs/heads/mybranch` | `/myfolder`
+`myrepo.git#abcdef:myfolder` | `sha1 = abcdef` | `/myfolder`
+
 Instead of specifying a context, you can pass a single Dockerfile in the
 `URL` or pipe the file in via `STDIN`.  To pipe a Dockerfile from `STDIN`: