Issue #28496: Mark up constants 0, 1 and -1 that denote return values or
special input values as literal text.
diff --git a/Doc/c-api/file.rst b/Doc/c-api/file.rst
index bbd4223..e8bc6bf 100644
--- a/Doc/c-api/file.rst
+++ b/Doc/c-api/file.rst
@@ -136,7 +136,7 @@
 
 .. c:function:: int PyFile_SetEncoding(PyFileObject *p, const char *enc)
 
-   Set the file's encoding for Unicode output to *enc*. Return 1 on success and 0
+   Set the file's encoding for Unicode output to *enc*. Return ``1`` on success and ``0``
    on failure.
 
    .. versionadded:: 2.3
@@ -145,7 +145,7 @@
 .. c:function:: int PyFile_SetEncodingAndErrors(PyFileObject *p, const char *enc, *errors)
 
    Set the file's encoding for Unicode output to *enc*, and its error
-   mode to *err*. Return 1 on success and 0 on failure.
+   mode to *err*. Return ``1`` on success and ``0`` on failure.
 
    .. versionadded:: 2.6