Improve the document structure in several places

Change-Id: Icea6d0b0d9628eb171f5673b397f1db7f1c5c5b8
diff --git a/types.rst b/types.rst
index eace2c6..91f2519 100644
--- a/types.rst
+++ b/types.rst
@@ -3,118 +3,118 @@
 TLV-TYPE number assignments
 ---------------------------
 
-+---------------------------------------------+------------------+-----------------+
-| Type                                        | Assigned number  | Assigned number |
-|                                             | (decimal)        | (hexadecimal)   |
-+=============================================+==================+=================+
-|                      **Packet types**                                            |
-+---------------------------------------------+------------------+-----------------+
-| Interest                                    | 5                | 0x05            |
-+---------------------------------------------+------------------+-----------------+
-| Data                                        | 6                | 0x06            |
-+---------------------------------------------+------------------+-----------------+
-|                      **Common fields**                                           |
-+---------------------------------------------+------------------+-----------------+
-| Name                                        | 7                | 0x07            |
-+---------------------------------------------+------------------+-----------------+
-|                      `Name component types`_                                     |
-+---------------------------------------------+------------------+-----------------+
-| GenericNameComponent                        | 8                | 0x08            |
-+---------------------------------------------+------------------+-----------------+
-| ImplicitSha256DigestComponent               | 1                | 0x01            |
-+---------------------------------------------+------------------+-----------------+
-| ParametersSha256DigestComponent             | 2                | 0x02            |
-+---------------------------------------------+------------------+-----------------+
-| KeywordNameComponent                        | 32 (non-critical)| 0x20            |
-+---------------------------------------------+------------------+-----------------+
-| SegmentNameComponent                        | 50 (non-critical)| 0x32            |
-+---------------------------------------------+------------------+-----------------+
-| ByteOffsetNameComponent                     | 52 (non-critical)| 0x34            |
-+---------------------------------------------+------------------+-----------------+
-| VersionNameComponent                        | 54 (non-critical)| 0x36            |
-+---------------------------------------------+------------------+-----------------+
-| TimestampNameComponent                      | 56 (non-critical)| 0x38            |
-+---------------------------------------------+------------------+-----------------+
-| SequenceNumNameComponent                    | 58 (non-critical)| 0x3a            |
-+---------------------------------------------+------------------+-----------------+
-|                     **Interest packet**                                          |
-+---------------------------------------------+------------------+-----------------+
-| CanBePrefix                                 | 33               | 0x21            |
-+---------------------------------------------+------------------+-----------------+
-| MustBeFresh                                 | 18               | 0x12            |
-+---------------------------------------------+------------------+-----------------+
-| ForwardingHint                              | 30               | 0x1e            |
-+---------------------------------------------+------------------+-----------------+
-| Nonce                                       | 10               | 0x0a            |
-+---------------------------------------------+------------------+-----------------+
-| InterestLifetime                            | 12               | 0x0c            |
-+---------------------------------------------+------------------+-----------------+
-| HopLimit                                    | 34 (non-critical)| 0x22            |
-+---------------------------------------------+------------------+-----------------+
-| ApplicationParameters                       | 36 (non-critical)| 0x24            |
-+---------------------------------------------+------------------+-----------------+
-| InterestSignatureInfo                       | 44 (non-critical)| 0x2c            |
-+---------------------------------------------+------------------+-----------------+
-| InterestSignatureValue                      | 46 (non-critical)| 0x2e            |
-+---------------------------------------------+------------------+-----------------+
-|                      **Data packet**                                             |
-+---------------------------------------------+------------------+-----------------+
-| MetaInfo                                    | 20               | 0x14            |
-+---------------------------------------------+------------------+-----------------+
-| Content                                     | 21               | 0x15            |
-+---------------------------------------------+------------------+-----------------+
-| SignatureInfo                               | 22               | 0x16            |
-+---------------------------------------------+------------------+-----------------+
-| SignatureValue                              | 23               | 0x17            |
-+---------------------------------------------+------------------+-----------------+
-|                      **Data/MetaInfo**                                           |
-+---------------------------------------------+------------------+-----------------+
-| ContentType                                 | 24               | 0x18            |
-+---------------------------------------------+------------------+-----------------+
-| FreshnessPeriod                             | 25               | 0x19            |
-+---------------------------------------------+------------------+-----------------+
-| FinalBlockId                                | 26               | 0x1a            |
-+---------------------------------------------+------------------+-----------------+
-|                     **Signature**                                                |
-+---------------------------------------------+------------------+-----------------+
-| SignatureType                               | 27               | 0x1b            |
-+---------------------------------------------+------------------+-----------------+
-| KeyLocator                                  | 28               | 0x1c            |
-+---------------------------------------------+------------------+-----------------+
-| KeyDigest                                   | 29               | 0x1d            |
-+---------------------------------------------+------------------+-----------------+
-| SignatureNonce                              | 38 (non-critical)| 0x26            |
-+---------------------------------------------+------------------+-----------------+
-| SignatureTime                               | 40 (non-critical)| 0x28            |
-+---------------------------------------------+------------------+-----------------+
-| SignatureSeqNum                             | 42 (non-critical)| 0x2a            |
-+---------------------------------------------+------------------+-----------------+
-|                     **Link Object**                                              |
-+---------------------------------------------+------------------+-----------------+
-| Delegation                                  | 31               | 0x1f            |
-+---------------------------------------------+------------------+-----------------+
-| Preference                                  | 30               | 0x1e            |
-+---------------------------------------------+------------------+-----------------+
-|                     `NDN Certificates`_                                          |
-+---------------------------------------------+------------------+-----------------+
-| ValidityPeriod                              | 253              | 0xfd            |
-+---------------------------------------------+------------------+-----------------+
-| NotBefore                                   | 254              | 0xfe            |
-+---------------------------------------------+------------------+-----------------+
-| NotAfter                                    | 255              | 0xff            |
-+---------------------------------------------+------------------+-----------------+
-| AdditionalDescription (non-critical)        | 258              | 0x0102          |
-+---------------------------------------------+------------------+-----------------+
-| DescriptionEntry                            | 512              | 0x0200          |
-+---------------------------------------------+------------------+-----------------+
-| DescriptionKey                              | 513              | 0x0201          |
-+---------------------------------------------+------------------+-----------------+
-| DescriptionValue                            | 514              | 0x0202          |
-+---------------------------------------------+------------------+-----------------+
++---------------------------------------------+--------------------+-----------------+
+| Type                                        | Assigned number    | Assigned number |
+|                                             | (decimal)          | (hexadecimal)   |
++=============================================+====================+=================+
+|                      **Packet types**                                              |
++---------------------------------------------+--------------------+-----------------+
+| Interest                                    | 5                  | 0x05            |
++---------------------------------------------+--------------------+-----------------+
+| Data                                        | 6                  | 0x06            |
++---------------------------------------------+--------------------+-----------------+
+|                      **Common fields**                                             |
++---------------------------------------------+--------------------+-----------------+
+| Name                                        | 7                  | 0x07            |
++---------------------------------------------+--------------------+-----------------+
+|                      |Name components|_                                            |
++---------------------------------------------+--------------------+-----------------+
+| GenericNameComponent                        | 8                  | 0x08            |
++---------------------------------------------+--------------------+-----------------+
+| ImplicitSha256DigestComponent               | 1                  | 0x01            |
++---------------------------------------------+--------------------+-----------------+
+| ParametersSha256DigestComponent             | 2                  | 0x02            |
++---------------------------------------------+--------------------+-----------------+
+| KeywordNameComponent                        | 32 (non-critical)  | 0x20            |
++---------------------------------------------+--------------------+-----------------+
+| SegmentNameComponent                        | 50 (non-critical)  | 0x32            |
++---------------------------------------------+--------------------+-----------------+
+| ByteOffsetNameComponent                     | 52 (non-critical)  | 0x34            |
++---------------------------------------------+--------------------+-----------------+
+| VersionNameComponent                        | 54 (non-critical)  | 0x36            |
++---------------------------------------------+--------------------+-----------------+
+| TimestampNameComponent                      | 56 (non-critical)  | 0x38            |
++---------------------------------------------+--------------------+-----------------+
+| SequenceNumNameComponent                    | 58 (non-critical)  | 0x3a            |
++---------------------------------------------+--------------------+-----------------+
+|                      **Interest packet**                                           |
++---------------------------------------------+--------------------+-----------------+
+| CanBePrefix                                 | 33                 | 0x21            |
++---------------------------------------------+--------------------+-----------------+
+| MustBeFresh                                 | 18                 | 0x12            |
++---------------------------------------------+--------------------+-----------------+
+| ForwardingHint                              | 30                 | 0x1e            |
++---------------------------------------------+--------------------+-----------------+
+| Nonce                                       | 10                 | 0x0a            |
++---------------------------------------------+--------------------+-----------------+
+| InterestLifetime                            | 12                 | 0x0c            |
++---------------------------------------------+--------------------+-----------------+
+| HopLimit                                    | 34 (non-critical)  | 0x22            |
++---------------------------------------------+--------------------+-----------------+
+| ApplicationParameters                       | 36 (non-critical)  | 0x24            |
++---------------------------------------------+--------------------+-----------------+
+| InterestSignatureInfo                       | 44 (non-critical)  | 0x2c            |
++---------------------------------------------+--------------------+-----------------+
+| InterestSignatureValue                      | 46 (non-critical)  | 0x2e            |
++---------------------------------------------+--------------------+-----------------+
+|                      **Data packet**                                               |
++---------------------------------------------+--------------------+-----------------+
+| MetaInfo                                    | 20                 | 0x14            |
++---------------------------------------------+--------------------+-----------------+
+| Content                                     | 21                 | 0x15            |
++---------------------------------------------+--------------------+-----------------+
+| SignatureInfo                               | 22                 | 0x16            |
++---------------------------------------------+--------------------+-----------------+
+| SignatureValue                              | 23                 | 0x17            |
++---------------------------------------------+--------------------+-----------------+
+|                      **MetaInfo**                                                  |
++---------------------------------------------+--------------------+-----------------+
+| ContentType                                 | 24                 | 0x18            |
++---------------------------------------------+--------------------+-----------------+
+| FreshnessPeriod                             | 25                 | 0x19            |
++---------------------------------------------+--------------------+-----------------+
+| FinalBlockId                                | 26                 | 0x1a            |
++---------------------------------------------+--------------------+-----------------+
+|                      **Signature**                                                 |
++---------------------------------------------+--------------------+-----------------+
+| SignatureType                               | 27                 | 0x1b            |
++---------------------------------------------+--------------------+-----------------+
+| KeyLocator                                  | 28                 | 0x1c            |
++---------------------------------------------+--------------------+-----------------+
+| KeyDigest                                   | 29                 | 0x1d            |
++---------------------------------------------+--------------------+-----------------+
+| SignatureNonce                              | 38 (non-critical)  | 0x26            |
++---------------------------------------------+--------------------+-----------------+
+| SignatureTime                               | 40 (non-critical)  | 0x28            |
++---------------------------------------------+--------------------+-----------------+
+| SignatureSeqNum                             | 42 (non-critical)  | 0x2a            |
++---------------------------------------------+--------------------+-----------------+
+|                      **Link Object**                                               |
++---------------------------------------------+--------------------+-----------------+
+| Delegation                                  | 31                 | 0x1f            |
++---------------------------------------------+--------------------+-----------------+
+| Preference                                  | 30                 | 0x1e            |
++---------------------------------------------+--------------------+-----------------+
+|                      |Certificate|_                                                |
++---------------------------------------------+--------------------+-----------------+
+| ValidityPeriod                              | 253                | 0xfd            |
++---------------------------------------------+--------------------+-----------------+
+| NotBefore                                   | 254                | 0xfe            |
++---------------------------------------------+--------------------+-----------------+
+| NotAfter                                    | 255                | 0xff            |
++---------------------------------------------+--------------------+-----------------+
+| AdditionalDescription                       | 258 (non-critical) | 0x0102          |
++---------------------------------------------+--------------------+-----------------+
+| DescriptionEntry                            | 512                | 0x0200          |
++---------------------------------------------+--------------------+-----------------+
+| DescriptionKey                              | 513                | 0x0201          |
++---------------------------------------------+--------------------+-----------------+
+| DescriptionValue                            | 514                | 0x0202          |
++---------------------------------------------+--------------------+-----------------+
 
 .. note::
-    The ABNF grammar of this specification denotes the TLV-TYPE of element ``X`` as ``X-TYPE``.
-    For example, ``INTEREST-TYPE`` means ``%x05``, the TLV-TYPE of ``Interest`` encoded in ``VAR-NUMBER-1`` format.
+   The ABNF grammar of this specification denotes the TLV-TYPE of element ``X`` as ``X-TYPE``.
+   For example, ``INTEREST-TYPE`` means ``%x05``, the TLV-TYPE of ``Interest`` encoded in ``VAR-NUMBER-1`` format.
 
 .. _type reservations:
 
@@ -124,24 +124,24 @@
 +----------------+-----------------------------------------------------------+
 | Number range   | Designation                                               |
 +================+===========================================================+
-| 9              | Reserved, formerly `Selectors`                            |
+| 9              | Reserved, formerly *Selectors*                            |
 +----------------+-----------------------------------------------------------+
-| 11             | Reserved, formerly `Scope`                                |
+| 11             | Reserved, formerly *Scope*                                |
 +----------------+-----------------------------------------------------------+
-| 13             | Reserved, formerly `MinSuffixComponents`                  |
+| 13             | Reserved, formerly *MinSuffixComponents*                  |
 +----------------+-----------------------------------------------------------+
-| 14             | Reserved, formerly `MaxSuffixComponents`                  |
+| 14             | Reserved, formerly *MaxSuffixComponents*                  |
 +----------------+-----------------------------------------------------------+
-| 15             | Reserved, formerly `PublisherPublicKeyLocator`            |
+| 15             | Reserved, formerly *PublisherPublicKeyLocator*            |
 +----------------+-----------------------------------------------------------+
-| 16             | Reserved, formerly `Exclude`                              |
+| 16             | Reserved, formerly *Exclude*                              |
 +----------------+-----------------------------------------------------------+
-| 17             | Reserved, formerly `ChildSelector`                        |
+| 17             | Reserved, formerly *ChildSelector*                        |
 +----------------+-----------------------------------------------------------+
-| 19             | Reserved, formerly `Any`                                  |
+| 19             | Reserved, formerly *Any*                                  |
 +----------------+-----------------------------------------------------------+
 | [80, 100]      | Reserved for assignments related to local-link data       |
-|                | processing, e.g., `NDNLP`_, etc. (1-byte encoding)        |
+|                | processing, e.g., NDNLP_ (1-byte encoding)                |
 +----------------+-----------------------------------------------------------+
 | all other      |                                                           |
 | numbers in     |                                                           |
@@ -150,7 +150,7 @@
 | [128, 252]     | For application use (1-byte encoding)                     |
 +----------------+-----------------------------------------------------------+
 | [800, 1000]    | Reserved for assignments related to local-link data       |
-|                | processing, e.g., `NDNLP`_, etc. (3-byte encoding)        |
+|                | processing, e.g., NDNLP_ (3-byte encoding)                |
 +----------------+-----------------------------------------------------------+
 | all other      |                                                           |
 | numbers in     |                                                           |
@@ -161,6 +161,8 @@
 
 .. _NDNLP: https://redmine.named-data.net/projects/nfd/wiki/NDNLPv2
 
-.. _NDN Certificates: https://named-data.net/doc/ndn-cxx/current/specs/certificate-format.html
+.. |Name components| replace:: **Name components**
+.. _Name components: https://redmine.named-data.net/projects/ndn-tlv/wiki/NameComponentType
 
-.. _Name component types: https://redmine.named-data.net/projects/ndn-tlv/wiki/NameComponentType
+.. |Certificate| replace:: **Certificate**
+.. _Certificate: https://named-data.net/doc/ndn-cxx/current/specs/certificate-format.html