2.7 -> 3.1 versionchanges.
diff --git a/Doc/c-api/init.rst b/Doc/c-api/init.rst
index ab4734f..299af7f 100644
--- a/Doc/c-api/init.rst
+++ b/Doc/c-api/init.rst
@@ -824,8 +824,7 @@
    other system thread.  If it is a Python thread, it doesn't matter if it holds
    the global interpreter lock or not.
 
-   .. versionadded:: 2.7
-
+   .. versionadded:: 3.1
 
 
 .. _profiling:
diff --git a/Doc/library/binascii.rst b/Doc/library/binascii.rst
index dffdd81..8488743 100644
--- a/Doc/library/binascii.rst
+++ b/Doc/library/binascii.rst
@@ -123,10 +123,6 @@
    return value is the correct 32bit binary representation
    regardless of sign.
 
-.. versionchanged:: 3.0
-   The return value is unsigned and in the range [0, 2**32-1]
-   regardless of platform.
-
 
 .. function:: b2a_hex(data)
               hexlify(data)
diff --git a/Doc/library/gc.rst b/Doc/library/gc.rst
index 6929a3d..9092145 100644
--- a/Doc/library/gc.rst
+++ b/Doc/library/gc.rst
@@ -151,7 +151,7 @@
       >>> gc.is_tracked({"a": []})
       True
 
-   .. versionadded:: 2.7
+   .. versionadded:: 3.1
 
 
 The following variable is provided for read-only access (you can mutate its
diff --git a/Doc/library/hashlib.rst b/Doc/library/hashlib.rst
index 36f386c..69facce 100644
--- a/Doc/library/hashlib.rst
+++ b/Doc/library/hashlib.rst
@@ -105,7 +105,7 @@
    concatenation of all the arguments: ``m.update(a); m.update(b)`` is
    equivalent to ``m.update(a+b)``.
 
-   .. versionchanged:: 2.7
+   .. versionchanged:: 3.1
 
       The Python GIL is released to allow other threads to run while
       hash updates on data larger than 2048 bytes is taking place when
diff --git a/Doc/library/pdb.rst b/Doc/library/pdb.rst
index 0b29c2c..678ae28 100644
--- a/Doc/library/pdb.rst
+++ b/Doc/library/pdb.rst
@@ -144,7 +144,7 @@
 
       import pdb; pdb.Pdb(skip=['django.*']).set_trace()
 
-   .. versionadded:: 2.7
+   .. versionadded:: 3.1
       The *skip* argument.
 
    .. method:: run(statement[, globals[, locals]])
diff --git a/Doc/library/test.rst b/Doc/library/test.rst
index 2da63ac..353715b 100644
--- a/Doc/library/test.rst
+++ b/Doc/library/test.rst
@@ -389,7 +389,7 @@
    manager all changes to environment variables done through this instance will
    be rolled back.
 
-   .. versionchanged:: 2.7
+   .. versionchanged:: 3.1
       Added dictionary interface.
 
 .. method:: EnvironmentVarGuard.set(envvar, value)
diff --git a/Doc/library/unittest.rst b/Doc/library/unittest.rst
index b7fb279..675114a 100644
--- a/Doc/library/unittest.rst
+++ b/Doc/library/unittest.rst
@@ -863,7 +863,7 @@
       This signals a test failure if *expr1* and *expr2* don't evaluate to the same
       object.
 
-      .. versionadded:: 2.7
+      .. versionadded:: 3.1
 
 
    .. method:: assertIsNot(expr1, expr2[, msg])
@@ -872,7 +872,7 @@
       This signals a test failure if *expr1* and *expr2* evaluate to the same
       object.
 
-      .. versionadded:: 2.7
+      .. versionadded:: 3.1
 
 
    .. method:: assertFalse(expr[, msg])
diff --git a/Doc/library/zlib.rst b/Doc/library/zlib.rst
index 2ab1450..030f706 100644
--- a/Doc/library/zlib.rst
+++ b/Doc/library/zlib.rst
@@ -51,10 +51,6 @@
    return value is the correct 32bit binary representation
    regardless of sign.
 
-.. versionchanged:: 3.0
-   The return value is unsigned and in the range [0, 2**32-1]
-   regardless of platform.
-
 
 .. function:: compress(string[, level])
 
@@ -96,10 +92,6 @@
    return value is the correct 32bit binary representation
    regardless of sign.
 
-.. versionchanged:: 3.0
-   The return value is unsigned and in the range [0, 2**32-1]
-   regardless of platform.
-
 
 .. function:: decompress(string[, wbits[, bufsize]])