Doc: Pacemaker Explained: Document limitation of pcmk-init.env parsing

We can resolve these limitations if there's ever a need. For now, it's
not worth the trouble of implementing and testing these missing
capabilities.

Signed-off-by: Reid Wahl <[email protected]>

Author: nrwahl2

doc/sphinx/Pacemaker_Explained/collective.rst

@@ -1094,11 +1094,12 @@ greater than zero.
    * Environment variables whose value is the same regardless of the underlying host
      may be set using the container element's ``options`` attribute.
    * If you want variables to have host-specific values, you can use the
-     :ref:`storage-mapping <s-bundle-storage>` element to map a file on the host as
-     ``/etc/pacemaker/pcmk-init.env`` in the container *(since 2.0.3)*.
-     Pacemaker Remote will parse this file as a shell-like format, with
-     variables set as NAME=VALUE, ignoring blank lines and comments starting
-     with "#".
+     :ref:`storage-mapping <s-bundle-storage>` element to map a file on the host
+     as |PCMK_INIT_ENV_FILE| in the container *(since 2.0.3)*. Pacemaker Remote
+     will parse this file in a manner similar to a POSIX shell, with variables
+     set as NAME=VALUE, ignoring blank lines and comments starting with ``#``.
+     An assignment may not span multiple lines, and multiple assignments per
+     line are not supported.
 
 .. important::