diff --git a/doc/reference/devicetree/index.rst b/doc/reference/devicetree/index.rst
index cea67c9..11c43af 100644
--- a/doc/reference/devicetree/index.rst
+++ b/doc/reference/devicetree/index.rst
@@ -108,6 +108,44 @@
 .. doxygengroup:: devicetree-generic-exist
    :project: Zephyr
 
+.. _devicetree-dep-ord:
+
+Inter-node dependencies
+=======================
+
+The ``devicetree.h`` API has some support for tracking dependencies between
+nodes. Dependency tracking relies on a binary "depends on" relation between
+devicetree nodes, which is defined as the `transitive closure
+<https://en.wikipedia.org/wiki/Transitive_closure>`_ of the following "directly
+depends on" relation:
+
+- every non-root node directly depends on its parent node
+- a node directly depends on any nodes its properties refer to by phandle
+- a node directly depends on its ``interrupt-parent`` if it has an
+  ``interrupts`` property
+
+A *dependency ordering* of a devicetree is a list of its nodes, where each node
+``n`` appears earlier in the list than any nodes that depend on ``n``. A node's
+*dependency ordinal* is then its zero-based index in that list. Thus, for two
+distinct devicetree nodes ``n1`` and ``n2`` with dependency ordinals ``d1`` and
+``d2``, we have:
+
+- ``d1 != d2``
+- if ``n1`` depends on ``n2``, then ``d1 > d2``
+- ``d1 > d2`` does **not** necessarily imply that ``n1`` depends on ``n2``
+
+The Zephyr build system chooses a dependency ordering of the final devicetree
+and assigns a dependency ordinal to each node. Dependency related information
+can be accessed using the following macros. The exact dependency ordering
+chosen is an implementation detail, but cyclic dependencies are detected and
+cause errors, so it's safe to assume there are none when using these macros.
+
+There are instance number-based conveniences as well; see
+:c:func:`DT_INST_DEP_ORD` and subsequent documentation.
+
+.. doxygengroup:: devicetree-dep-ord
+   :project: Zephyr
+
 Bus helpers
 ===========