@@ -201,7 +201,8 @@ and a "context".

 The files at `PATH` or `URL` are called the "context" of the build. The build

 process may refer to any of the files in the context, for example when using an

 [*ADD*](/reference/builder/#dockerfile-add) instruction. When a single Dockerfile is

-given as `URL`, then no context is set.

+given as `URL` or is piped through STDIN (`docker build - < Dockerfile`), then

+no context is set.

 When a Git repository is set as `URL`, then the

 repository is used as the context. The Git repository is cloned with its

@@ -283,6 +284,13 @@ repository is used as Dockerfile. Note that you

 can specify an arbitrary Git repository by using the `git://`

 schema.

+> **Note:** `docker build` will return a `no such file or directory` error

+> if the file or directory does not exist in the uploaded context. This may

+> happen if there is no context, or if you specify a file that is elsewhere 

+> on the Host system. The context is limited to the current directory (and its

+> children) for security reasons, and to ensure repeatable builds on remote

+> Docker hosts. This is also the reason why `ADD ../file` will not work.

+

 ## commit

 Create a new image from a container᾿s changes