@@ -97,6 +97,9 @@ A Dockerfile is similar to a Makefile.

   exec form makes it possible to avoid shell string munging. The exec form makes

   it possible to **RUN** commands using a base image that does not contain `/bin/sh`.

+  Note that the exec form is parsed as a JSON array, which means that you must

+  use double-quotes (") around words not single-quotes (').

+

 **CMD**

   -- **CMD** has three forms:

@@ -120,6 +123,9 @@ A Dockerfile is similar to a Makefile.

   be executed when running the image.

   If you use the shell form of the **CMD**, the `<command>` executes in `/bin/sh -c`:

+  Note that the exec form is parsed as a JSON array, which means that you must

+  use double-quotes (") around words not single-quotes (').

+

   ```

   FROM ubuntu

   CMD echo "This is a test." | wc -