diff --git a/docs/CMakeLists.txt b/docs/CMakeLists.txt
index 657bbdd5..04c7fc08 100644
--- a/docs/CMakeLists.txt
+++ b/docs/CMakeLists.txt
@@ -44,6 +44,7 @@ set(unitsSphinxDocs
"${CMAKE_CURRENT_SOURCE_DIR}/_static/img/downcast_1.png"
"${CMAKE_CURRENT_SOURCE_DIR}/_static/img/downcast_2.png"
"${CMAKE_CURRENT_SOURCE_DIR}/_static/img/units.svg"
+ "${CMAKE_CURRENT_SOURCE_DIR}/_static/img/quantity_like.svg"
"${CMAKE_CURRENT_SOURCE_DIR}/CHANGELOG.md"
"${CMAKE_CURRENT_SOURCE_DIR}/design.rst"
"${CMAKE_CURRENT_SOURCE_DIR}/design/directories.rst"
@@ -88,6 +89,7 @@ set(unitsSphinxDocs
"${CMAKE_CURRENT_SOURCE_DIR}/framework/dimensions.rst"
"${CMAKE_CURRENT_SOURCE_DIR}/framework/quantities.rst"
"${CMAKE_CURRENT_SOURCE_DIR}/framework/quantity_kinds.rst"
+ "${CMAKE_CURRENT_SOURCE_DIR}/framework/quantity_like.rst"
"${CMAKE_CURRENT_SOURCE_DIR}/framework/quantity_points.rst"
"${CMAKE_CURRENT_SOURCE_DIR}/framework/text_output.rst"
"${CMAKE_CURRENT_SOURCE_DIR}/framework/units.rst"
diff --git a/docs/_static/img/quantity_like.svg b/docs/_static/img/quantity_like.svg
new file mode 100644
index 00000000..bcc1c0ff
--- /dev/null
+++ b/docs/_static/img/quantity_like.svg
@@ -0,0 +1,37 @@
+
diff --git a/docs/framework.rst b/docs/framework.rst
index ba17d2e2..cacfa71b 100644
--- a/docs/framework.rst
+++ b/docs/framework.rst
@@ -12,6 +12,7 @@ Framework Basics
:maxdepth: 2
framework/basic_concepts
+ framework/quantity_like
framework/quantities
framework/quantity_points
framework/quantity_kinds
diff --git a/docs/framework/quantity_like.rst b/docs/framework/quantity_like.rst
new file mode 100644
index 00000000..f963fdc7
--- /dev/null
+++ b/docs/framework/quantity_like.rst
@@ -0,0 +1,51 @@
+.. namespace:: units
+
+Quantity-like Types
+===================
+
+.. raw:: html
+
+
+
+..
+ https://www.planttext.com
+
+ @startuml
+
+ skinparam monochrome true
+ skinparam shadowing false
+ skinparam backgroundColor #fcfcfc
+
+ hide members
+ hide circle
+
+ class quantity [[../framework/quantities.html]]
+ class quantity_point [[../framework/quantity_points.html]]
+ class quantity_kind [[../framework/quantity_kinds.html]]
+ class quantity_point_kind [[../framework/quantity_kinds.html#quantity-point-kinds]]
+
+ Rep <-- quantity : number()
+ quantity <-- quantity_point : relative()
+ quantity <-- quantity_kind : common()
+ quantity_kind <-- quantity_point_kind : relative()
+
+ @enduml
+
+
+[ISO80000]_ defines a :term:`quantity` as a:
+
+ Property of a phenomenon, body, or substance, where the property has a magnitude that can be expressed by
+ means of a number and a reference.
+
+You can use `quantity::number()` member function to get a concrete amount of a unit expressed with a specific
+representation type ``Rep``.
+
+:term:`Kind of quantity ` is defined as:
+
+ Aspect common to mutually comparable quantities.
+
+We can obtain a `quantity` with a `quantity_kind::common()` member function.
+
+`quantity_point` and `quantity_point_kind` are absolute quantities and quantity kinds relative to some
+specific origin. `quantity` and `quantity_point` types can be obtained from them using a ``relative()`` member
+function (`quantity_point::relative()`, `quantity_point_kind::relative()`).