diff --git a/docs/examples.rst b/docs/examples.rst
index b107aa7..c1ad084 100644
--- a/docs/examples.rst
+++ b/docs/examples.rst
@@ -45,10 +45,10 @@
    :emphasize-lines: 42,55-58,61,64,67,70,76
 
 
-Consumer that uses ndn::Scheduler
----------------------------------
+Consumer that uses Scheduler
+----------------------------
 
-The following example demonstrates how to use :ndn-cxx:`ndn::Scheduler` to schedule arbitrary
+The following example demonstrates how to use :ndn-cxx:`Scheduler` to schedule arbitrary
 events for execution at specific points of time.
 
 The library internally uses `boost::asio::io_service
@@ -57,7 +57,7 @@
 Data).  In addition to network-related operations, ``boost::asio::io_service`` can be used
 to execute any arbitrary callback within the processing thread (run either explicitly via
 ``io.run`` or implicitly via :ndn-cxx:`Face::processEvents` as in previous examples).
-:ndn-cxx:`ndn::Scheduler` is just a wrapper on top of ``boost::asio::io_service``,
+:ndn-cxx:`Scheduler` is just a wrapper on top of ``boost::asio::io_service``,
 allowing simple interface to schedule tasks at specific times.
 
 The highlighted lines in the example demonstrate all that is needed to express a second
diff --git a/docs/index.rst b/docs/index.rst
index fcfc521..291fb72 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -18,6 +18,7 @@
    INSTALL
    examples
    tutorials
+   specs
    manpages
 
 .. toctree::
@@ -39,8 +40,12 @@
    + :doc:`tutorials/security-library`
    + :doc:`tutorials/utils-ndn-regex`
    + :doc:`tutorials/security-validator-config`
-   + :doc:`tutorials/signed-interest`
-   + :doc:`tutorials/certificate-format`
+
+- :doc:`specs`
+
+   + :doc:`specs/signed-interest`
+   + :doc:`specs/certificate-format`
+   + :doc:`specs/safe-bag`
 
 - :doc:`manpages`
 
diff --git a/docs/specs.rst b/docs/specs.rst
new file mode 100644
index 0000000..ca5810b
--- /dev/null
+++ b/docs/specs.rst
@@ -0,0 +1,9 @@
+Specifications
+==============
+
+.. toctree::
+   :maxdepth: 2
+
+   specs/signed-interest
+   specs/certificate-format
+   specs/safe-bag
diff --git a/docs/tutorials/certificate-format.rst b/docs/specs/certificate-format.rst
similarity index 100%
rename from docs/tutorials/certificate-format.rst
rename to docs/specs/certificate-format.rst
diff --git a/docs/specs/safe-bag.rst b/docs/specs/safe-bag.rst
new file mode 100644
index 0000000..2542f8d
--- /dev/null
+++ b/docs/specs/safe-bag.rst
@@ -0,0 +1,27 @@
+Export/Import Credentials
+=========================
+
+Sometimes, one may need to export credentials (e.g., certificate and private key) from
+one machine, and import them into another machine.  This requires a secured container for
+sensitive information.  We define **SafeBag**, which contains both an NDN certificate
+(:doc:`version 2.0 <certificate-format>`) and the corresponding private
+key which is encrypted in `PKCS#8 format <https://tools.ietf.org/html/rfc5208>`_.
+
+The format of **SafeBag** is defined as:
+
+::
+
+    SafeBag ::= SAFE-BAG-TYPE TLV-LENGTH
+                  Certificate ; a data packet following certificate format spec
+                  EncryptedKeyBag ; private key encrypted in PKCS#8 format
+
+All TLV-TYPE codes are application specific:
+
++---------------------------------------------+-------------------+----------------+
+| TLV-TYPE                                    | Assigned code     | Assigned code  |
+|                                             | (decimal)         | (hexadecimal)  |
++=============================================+===================+================+
+| SafeBag                                     | 128               | 0x80           |
++---------------------------------------------+-------------------+----------------+
+| EncryptedKeyBag                             | 129               | 0x81           |
++---------------------------------------------+-------------------+----------------+
diff --git a/docs/tutorials/signed-interest.rst b/docs/specs/signed-interest.rst
similarity index 100%
rename from docs/tutorials/signed-interest.rst
rename to docs/specs/signed-interest.rst
diff --git a/docs/tutorials.rst b/docs/tutorials.rst
index d4bc089..c3c1ca1 100644
--- a/docs/tutorials.rst
+++ b/docs/tutorials.rst
@@ -7,5 +7,3 @@
    tutorials/security-library
    tutorials/utils-ndn-regex
    tutorials/security-validator-config
-   tutorials/signed-interest
-   tutorials/certificate-format
diff --git a/docs/tutorials/security-library.rst b/docs/tutorials/security-library.rst
index 30d3de0..8ee8d40 100644
--- a/docs/tutorials/security-library.rst
+++ b/docs/tutorials/security-library.rst
@@ -251,7 +251,7 @@
 %%%%%%%%%%%%%%%%%
 
 The process of signing Interests according to the :doc:`Signed Interest specification
-<signed-interest>` is exactly the same as the process of signing Data packets:
+<../specs/signed-interest>` is exactly the same as the process of signing Data packets:
 
 .. code-block:: cpp