Disambiguate header targets

Author: AA-Turner

peps/pep-0780.rst

@@ -29,9 +29,9 @@ when the dependency should be used.
 This PEP extends the environment markers to allow specifying dependencies
 based on specific ABI features of the Python interpreter.
 For this, it defines a set of `ABI Features`_ and specifies how they are made
-available via an `addition to the Python Standard Library <sys.abi_features_>`_
+available via an `addition to the Python Standard Library <pep-780-sys.abi_features_>`_
 in the form of a new attribute :data:`!sys.abi_features`, as well as for
-`environment markers <sys_abi_features_>`_ as a new marker variable,
+`environment markers <pep-780-sys_abi_features_>`_ as a new marker variable,
 ``sys_abi_features``.
 
 Motivation
@@ -197,7 +197,7 @@ which case there MUST be at most one feature present.
     build [#bitness]_. If the bitness is unknown or neither 32-bit nor 64-bit,
     this feature MUST NOT be present.
 
-.. _sys.abi_features:
+.. _pep-780-sys.abi_features:
 
 The :data:`!sys.abi_features` Attribute
 ---------------------------------------
@@ -225,7 +225,7 @@ defined in this PEP or in a subsequent PEP.
 An example value would be ``sys.abi_features == frozenset({"free-threading",
 "debug", "32-bit"})`` on a free-threaded debug build for win32.
 
-.. _sys_abi_features:
+.. _pep-780-sys_abi_features:
 
 The ``sys_abi_features`` Environment Marker
 -------------------------------------------