-1. ``RMR_RETRY_TIMES`` the number of times failed rmr operations such as
-timeouts and send failures should be retried before A1 gives up and
-returns a 503. The default is ``4``.
+1. ``A1_RMR_RETRY_TIMES``: the number of times failed rmr operations such as timeouts and send failures should be retried before A1 gives up and returns a 503. The default is ``4``.
+
+2. ``INSTANCE_DELETE_NO_RESP_TTL``: Please refer to the delete flowchart in docs/; this is ``T1`` there. The default is 5 (seconds). Basically, the number of seconds that a1 waits to remove an instance from the database after a delete is called in the case that no downstream apps responded.
+
+3. ``INSTANCE_DELETE_RESP_TTL``: Please refer to the delete flowchart in docs/; this is ``T2`` there. The default is 5 (seconds). Basically, the number of seconds that a1 waits to remove an instance from the database after a delete is called in the case that downstream apps responded.