Explain that using shell functionality is forbidden. [skip ci]
@@ -304,3 +304,9 @@ line switches.
- Prefer specific solutions to generic frameworks. Solve the end
user's problems rather than providing them tools to do it
themselves.
+
+- Never use features of the Unix shell (or Windows shell for that
+ matter). Doing things like forwaring output with `>` or invoking
+ multiple commands with `&&` are not permitted. Whenever these sorts
+ of requirements show up, write an internal Python script with the
+ desired functionality and use that instead.
