diff --git a/doc/developer-guide/internal-libraries/index.en.rst b/doc/developer-guide/internal-libraries/index.en.rst
index 81a75287135..32dfb332b68 100644
--- a/doc/developer-guide/internal-libraries/index.en.rst
+++ b/doc/developer-guide/internal-libraries/index.en.rst
@@ -28,13 +28,13 @@ development team.
 .. toctree::
    :maxdepth: 1
 
-   TextView.en
+   AcidPtr.en
+   ArgParser.en
+   Extendible.en
+   MemArena.en
    MemSpan.en
-   scalar.en
+   TextView.en
    buffer-writer.en
-   intrusive-list.en
    intrusive-hash-map.en
-   MemArena.en
-   AcidPtr.en
-   Extendible.en
-   ArgParser.en
+   intrusive-list.en
+   scalar.en
diff --git a/doc/developer-guide/internal-libraries/intrusive-hash-map.en.rst b/doc/developer-guide/internal-libraries/intrusive-hash-map.en.rst
index 8b5fbe36f7c..150e9a35942 100644
--- a/doc/developer-guide/internal-libraries/intrusive-hash-map.en.rst
+++ b/doc/developer-guide/internal-libraries/intrusive-hash-map.en.rst
@@ -33,17 +33,15 @@ In order to optimize lookup, the container can increase the number of buckets us
 be to be automatic or only done explicitly.
 
 Usage
-*****
+=====
 
 To use an :class:`IntrusiveHashMap` the element must provide support for the container. This is done
 through an associated descriptor class which provides the operations needed to manipulate the elements
 in the container.
 
-Examples
-========
 
 Details
-*******
+=======
 
 .. class:: template < typename H > IntrusiveHashMap
 
@@ -161,7 +159,7 @@ Details
       modify them. In such cases this method provides a safe way to invoke such mechanisms.
 
 Design Notes
-************
+============
 
 This is a refresh of an previously existing class, :code:`TSHahTable`. The switch to C++ 11 and then
 C++ 17 made it possible to do much better in terms of the internal implementation and API. The
@@ -176,7 +174,7 @@ class can be removed. Elements with equal keys can be handled in the same way as
 containers, via iterator ranges, instead of a custom pseudo-iterator class.
 
 Notes on :func:`IntrusiveHashMap::apply`
-========================================
+----------------------------------------
 
 This was added after some experience with use of the container. Initially it was added to make
 cleaning up the container easier. Without it, cleanup looks like ::
diff --git a/doc/developer-guide/internal-libraries/intrusive-list.en.rst b/doc/developer-guide/internal-libraries/intrusive-list.en.rst
index 2d49f44fa1a..75ab3b1d013 100644
--- a/doc/developer-guide/internal-libraries/intrusive-list.en.rst
+++ b/doc/developer-guide/internal-libraries/intrusive-list.en.rst
@@ -28,7 +28,7 @@ iterators automatically convert to pointer as in normal use of this class the co
 will be referenced by pointers.
 
 Definition
-**********
+==========
 
 .. class:: template < typename L > IntrusiveDList
 
@@ -118,7 +118,7 @@ Definition
       the end iterator is returned.
 
 Usage
-*****
+=====
 
 An instance of :class:`IntrusiveDList` acts as a container for items, maintaining a doubly linked
 list / queue of the objects and tracking the number of objects in the container. There are methods
@@ -212,7 +212,7 @@ While this can be done directly with :code:`reinterpret_cast<>`, use of :code:`t
 typographic errors and warnings about type punning caused by :code:`-fstrict-aliasing`.
 
 Design Notes
-************
+============
 
 The historic goal of this class is to replace the :code:`DLL` list support. The benefits of this are
 
diff --git a/doc/developer-guide/internal-libraries/scalar.en.rst b/doc/developer-guide/internal-libraries/scalar.en.rst
index 185fe06f3d6..28b9c0056f3 100644
--- a/doc/developer-guide/internal-libraries/scalar.en.rst
+++ b/doc/developer-guide/internal-libraries/scalar.en.rst
@@ -34,7 +34,7 @@ have the same memory footprint as the underlying integer storage type. It is int
 lengthy and error prone hand optimizations used to handle related values of different scales.
 
 Definition
-**********
+==========
 
 TS.Scalar consists primarily of the template class :code:`Scalar`. Instances of :class:`Scalar` hold
 a *count* and represent a *value* which is the *count* multiplied by :arg:`SCALE`. Note this
@@ -85,14 +85,14 @@ quantizes the values that can be represented by an instance.
       Set the count to :arg:`c`.
 
 Usage
-******
+======
 
 In normal use a scalar evaluates to its value rather than its count. The goal is to provide an
 instance that appears to store unscaled values in a quantized way. The count is accessible if
 needed.
 
 Assignment
-==========
+----------
 
 Assigning values to, from, and between :class:`Scalar` instances is usually straightforward with a few simple rules.
 
@@ -151,7 +151,7 @@ as possible.
    a = round_down(2480); // a has count 24, value 2400.
 
 Arithmetic
-==========
+----------
 
 Arithmetic with scalars is based on the idea that a scalar represents its value. This value retains the
 scalar type for conversion checking but otherwise acts as the value. This makes using scalar