Actions to be performed in case of a disaster are not normally part of an
information security policy but part of a Disaster Recovery Plan (DRP).
Only personnel implicated in the plan should have a copy of the Disaster Recovery Plan
whereas everyone should be aware of the contents of the organization's information
security policy.
Source: ALLEN, Julia H., The CERT Guide to System and Network Security Practices,
Addison-Wesley, 2001, Appendix B, Practice-Level Policy Considerations (page 398).

Explanation/Reference:
In cryptography, a Caesar cipher, also known as Caesar's cipher, the shift cipher, Caesar's code or Caesar shift, is one of the simplest and most widely known encryption techniques. It is a type of substitution cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet. For example, with a left shift of 3, D would be replaced by A, E would become B, and so on. The method is named after Julius Caesar, who used it in his private correspondence.
The encryption step performed by a Caesar cipher is often incorporated as part of more complex schemes, such as the Vigenère cipher, and still has modern application in the ROT13 system. As with all single alphabet substitution ciphers, the Caesar cipher is easily broken and in modern practice offers essentially no communication security.
The following answer were incorrect:
The Jefferson disk, or wheel cipher as Thomas Jefferson named it, also known as the Bazeries Cylinder, is a cipher system using a set of wheels or disks, each with the 26 letters of the alphabet arranged around their edge. The order of the letters is different for each disk and is usually scrambled in some random way.
Each disk is marked with a unique number. A hole in the centre of the disks allows them to be stacked on an axle. The disks are removable and can be mounted on the axle in any order desired. The order of the disks is the cipher key, and both sender and receiver must arrange the disks in the same predefined order.
Jefferson's device had 36 disks.
An Enigma machine is any of a family of related electro-mechanical rotor cipher machines used for the encryption and decryption of secret messages. Enigma was invented by the German engineer Arthur Scherbius at the end of World War I. The early models were used commercially from the early 1920s, and adopted by military and government services of several countries. Several different Enigma models were produced, but the German military models are the ones most commonly discussed.
SIGABA: In the history of cryptography, the ECM Mark II was a cipher machine used by the United States for message encryption from World War II until the 1950s. The machine was also known as the SIGABA or Converter M-134 by the Army, or CSP-888/889 by the Navy, and a modified Navy version was termed the CSP-2900. Like many machines of the era it used an electromechanical system of rotors in order to encipher messages, but with a number of security improvements over previous designs. No successful cryptanalysis of the machine during its service lifetime is publicly known.
Reference(s) used for this question:
http://en.wikipedia.org/wiki/Jefferson_disk
http://en.wikipedia.org/wiki/Sigaba
http://en.wikipedia.org/wiki/Enigma_machine

PPTP is an encapsulation protocol based on PPP that works at OSI layer 2 (Data Link) and that enables a single point-to-point connection, usually between a client and a server.
While PPTP depends on IP to establish its connection.
As currently implemented, PPTP encapsulates PPP packets using a modified version of the generic routing encapsulation (GRE) protocol, which gives PPTP to the flexibility of handling protocols other than IP, such as IPX and NETBEUI over IP networks.
PPTP does have some limitations:
It does not provide strong encryption for protecting data, nor does it support any token-based methods for authenticating users.
L2TP is derived from L2F and PPTP, not the opposite.

Section: Risk, Response and Recovery
Explanation/Reference:
A business continuity plan (BCP) focuses on sustaining an organization's business functions during and after a disruption. Information systems are considered in the BCP only in terms of their support to the larger business processes. The business recovery plan (BRP) addresses the restoration of business processes after an emergency. The BRP is similar to the BCP, but it typically lacks procedures to ensure continuity of critical processes throughout an emergency or disruption. The continuity of operations plan (COOP) focuses on restoring an organization's essential functions at an alternate site and performing those functions for up to 30 days before returning to normal operations. The disaster recovery plan (DRP) applies to major, usually catastrophic events that deny access to the normal facility for an extended period. A DRP is narrower in scope than an IT contingency plan in that it does not address minor disruptions that do not require relocation.
Source: SWANSON, Marianne, & al., National Institute of Standards and Technology (NIST), NIST Special Publication 800-34, Contingency Planning Guide for Information Technology Systems, December 2001 (page
8).

Explanation/Reference:
While neither CBK nor AIO3 use the term "screening router," they both discuss how the packet filtering capabilities of a router can be used to block traffic much like a packet filtering firewall. Krutz and Vine use this term on p. 90.
"A scanning router" is incorrect. This is a nonsense term to distract you.
"A shielding router" is incorrect. This is a nonsense term to distract you.
"A sniffing router" is incorrect. This is a nonsense term to distract you.
References:
CBK, p. 433
AIO3, pp.484 - 485