Guard: When Manual guard can be performed

- Added the information about when the manual guard can be
  performed i.e in few platforms, manual guard action maybe
  restricted in a certain system state.

- Added the new line between each glossary.

Signed-off-by: Ramesh Iyyar <rameshi1@in.ibm.com>
Change-Id: I13819643c79c5cd917af509a8851229a59ea1224
diff --git a/designs/guard-on-bmc.md b/designs/guard-on-bmc.md
index 14ef88d..3b07ec4 100644
--- a/designs/guard-on-bmc.md
+++ b/designs/guard-on-bmc.md
@@ -15,8 +15,10 @@
 ## Glossary
 **Guard**: Guarding the system against failures by permanently isolating faulty
 units.
+
 **Guard Records**: A file in the persistent storage with the list of
 permanently isolated components.
+
 **Manual guard**: An operation to manually add a unit to the list of isolated
 units. This operation is helpful in isolating a suspected component without
 physically removing it from the server.
@@ -93,6 +95,9 @@
 
 - List Guard:  List all the guarded components.
 
+**Note:** In few platforms may be the system or hardware is not in a state where
+guard operation can be performed either "permanently" or "temporarily".
+
 #### Guard Entry
 The properties of each guard entry will be part of this object
 Properties: