PEP 725: improve content of Examples section

Author: rgommers

peps/pep-0725.rst

@@ -598,7 +598,8 @@ normalization) follows the official `dependency groups specification`_.
 Examples
 --------
 
-These examples show what the ``[external]`` content for a number of packages is
+These examples show what the ``[external]`` table content for a number of
+packages, and the corresponding ``PKG-INFO``/``METADATA`` content (if any) is
 expected to be.
 
 cryptography 39.0
@@ -619,6 +620,8 @@ cryptography 39.0
       "dep:generic/libffi",
     ]
 
+``PKG-INFO`` / ``METADATA`` content: N/A.
+
 SciPy 1.10
 ''''''''''
 
@@ -639,6 +642,8 @@ SciPy 1.10
       "dep:virtual/interface/lapack@>=3.7.1",
     ]
 
+``PKG-INFO`` / ``METADATA`` content: N/A.
+
 Pillow 10.1.0
 '''''''''''''
 
@@ -668,6 +673,7 @@ Pillow 10.1.0
       "dep:generic/tk",
     ]
 
+``PKG-INFO`` / ``METADATA`` content: N/A.
 
 NAVis 1.4.0
 '''''''''''
@@ -752,12 +758,22 @@ PyEnchant 3.2.2
 
     [external]
     dependencies = [
-      # libenchant is needed on all platforms but only vendored into wheels on
-      # Windows, so on Windows the build backend should remove this external
-      # dependency from wheel metadata.
-      "dep:github/AbiWord/enchant",
+      # libenchant is needed on all platforms but vendored into wheels
+      # distributed on PyPI for Windows. Hence choose to encode that in
+      # the metadata. Note: there is no completely unambiguous way to do
+      # this; another choice is to leave out the environment marker in the
+      # source distribution and either live with the unnecessary ``METADATA``
+      # entry in the distributed Windows wheels, or to apply a patch to this
+      # metadata when building those wheels.
+      "dep:github/AbiWord/enchant; platform_system!='Windows'",
     ]
 
+``PKG-INFO`` / ``METADATA`` content:
+
+.. code::
+
+  Requires-External-Dep: dep:github/AbiWord/enchant; platform_system!="Windows"
+
 With dependency groups
 ''''''''''''''''''''''
 
@@ -771,6 +787,7 @@ With dependency groups
       "dep:generic/valgrind",
     ]
 
+``PKG-INFO`` / ``METADATA`` content: N/A.
 
 Backwards Compatibility
 =======================