diff --git a/api-guide/source/server_concepts.rst b/api-guide/source/server_concepts.rst
index ea2987148079..cb1288157d81 100644
--- a/api-guide/source/server_concepts.rst
+++ b/api-guide/source/server_concepts.rst
@@ -148,7 +148,7 @@ Server actions
 
 -  **Evacuate**
 
-   Should a compute node actually go offline, it can no longer report
+   Should a nova-compute service actually go offline, it can no longer report
    status about any of the servers on it. This means they'll be
    listed in an 'ACTIVE' state forever.
 
@@ -173,10 +173,10 @@ Server actions
    spawned in the virt layer and revert all changes, the original server
    will still be used from then on.
 
-   Also, there there is a periodic task configured by param
-   CONF.resize_confirm_window(in seconds), if this value is not 0, nova compute
+   Also, there there is a periodic task configured by configuration option
+   resize_confirm_window(in seconds), if this value is not 0, nova compute
    will check whether the server is in resized state longer than
-   CONF.resize_confirm_window, it will automatically confirm the resize
+   value of resize_confirm_window, it will automatically confirm the resize
    of the server.
 
 -  **Pause**, **Unpause**
@@ -223,13 +223,13 @@ Server actions
    Power off the given server first then detach all the resources associated
    to the server such as network and volumes, then delete the server.
 
-   CONF.reclaim_instance_interval (in seconds) decides whether the server to
-   be deleted will still be in the system. If this value is greater than 0,
-   the deleted server will not be deleted immediately, instead it will be put
-   into a queue until it's too old(deleted time greater than the value of
-   CONF.reclaim_instance_interval). Administrator is able to use Restore action
-   to recover the server from the delete queue. If the deleted server stays
-   more than the CONF.reclaim_instance_interval, it will be deleted by compute
+   The configuration option 'reclaim_instance_interval' (in seconds) decides whether
+   the server to be deleted will still be in the system. If this value is greater
+   than 0, the deleted server will not be deleted immediately, instead it will be
+   put into a queue until it's too old (deleted time greater than the value of
+   reclaim_instance_interval). Administrator is able to use Restore action to
+   recover the server from the delete queue. If the deleted server remains
+   longer than the value of reclaim_instance_interval, it will be deleted by compute
    service automatically.
 
 -  **Shelve**, **Shelve offload**, **Unshelve**
@@ -238,6 +238,13 @@ Server actions
    temporarily removed from the hypervisors. This allows its resources to
    be freed up for use by someone else.
 
+   By default the configuration option 'shelved_offload_time' is 0 and the shelved
+   server will be removed from the hypervisor immediately after shelve operation;
+   Otherwise, the resource will be kept for the value of 'shelved_offload_time'
+   (in seconds) so that during the time period the unshelve action will be faster,
+   then the periodic task will remove the server from hypervisor. Set the option
+   'shelved_offload_time' to -1 make it never offload.
+
    Shelve will power off the given server and take a snapshot if it is booted
    from image. The server can then be offloaded from the compute host and its
    resources deallocated. Offloading is done immediately if booted from volume,
@@ -255,10 +262,12 @@ Server actions
 -  **Lock**, **Unlock**
 
    Lock a server so no further actions are allowed to the server. This can
-   be done by either administrator or the server's owner.
+   be done by either administrator or the server's owner. By default, only owner
+   or administrator can lock the sever, and administrator can overwrite owner's lock.
 
-   Unlock will unlock an server in locked state so additional
-   operations can be performed on the server.
+   Unlock will unlock a server in locked state so additional
+   operations can be performed on the server. By default, only owner or
+   administrator can unlock the server.
 
 -  **Rescue**, **Unrescue**