diff --git a/nw/common.py b/nw/common.py
index 11546c88..826f7370 100644
--- a/nw/common.py
+++ b/nw/common.py
@@ -30,7 +30,9 @@ from datetime import datetime
 
 from PyQt5.QtWidgets import qApp
 
-from nw.constants import nwConst, nwUnicode
+from nw.constants import (
+    nwConst, nwUnicode, nwItemClass, nwItemType, nwItemLayout
+)
 
 logger = logging.getLogger(__name__)
 
@@ -103,11 +105,39 @@ def isHandle(theString):
         return False
     if len(theString) != 13:
         return False
-    invalidChar = False
     for c in theString:
         if c not in "0123456789abcdef":
-            invalidChar = True
-    return not invalidChar
+            return False
+    return True
+
+def isTitleTag(theString):
+    """Check if a string is a valid title string.
+    """
+    if not isinstance(theString, str):
+        return False
+    if len(theString) != 7:
+        return False
+    if not theString.startswith("T"):
+        return False
+    for c in theString[1:]:
+        if c not in "0123456789":
+            return False
+    return True
+
+def isItemClass(theString):
+    """Check if an item is a calid nwItemClass identifier.
+    """
+    return theString in nwItemClass.__members__
+
+def isItemType(theString):
+    """Check if an item is a calid nwItemType identifier.
+    """
+    return theString in nwItemType.__members__
+
+def isItemLayout(theString):
+    """Check if an item is a calid nwItemLayout identifier.
+    """
+    return theString in nwItemLayout.__members__
 
 def hexToInt(value, default=0):
     """Convert a hex string to an integer.
diff --git a/tests/test_base/test_base_common.py b/tests/test_base/test_base_common.py
index 79b6562a..4b076a64 100644
--- a/tests/test_base/test_base_common.py
+++ b/tests/test_base/test_base_common.py
@@ -26,7 +26,8 @@ import pytest
 from nw.common import (
     checkString, checkBool, checkInt, colRange, formatInt, transferCase,
     fuzzyTime, checkHandle, formatTimeStamp, formatTime, hexToInt,
-    makeFileNameSafe
+    makeFileNameSafe, isHandle, isTitleTag, isItemClass, isItemType,
+    isItemLayout
 )
 from tools import cmpList
 
@@ -88,6 +89,95 @@ def testBaseCommon_CheckHandle():
 
 # END Test testBaseCommon_CheckHandle
 
+@pytest.mark.base
+def testBaseCommon_IsHandle():
+    """Test the isHandle function.
+    """
+    assert isHandle("47666c91c7ccf")
+
+    assert not isHandle("47666C91C7CCF")
+    assert not isHandle("h7666c91c7ccf")
+    assert not isHandle("None")
+    assert not isHandle(None)
+    assert not isHandle("STUFF")
+
+# END Test testBaseCommon_IsHandle
+
+@pytest.mark.base
+def testBaseCommon_IsTitleTag():
+    """Test the isItemClass function.
+    """
+    assert isTitleTag("T123456")
+
+    assert not isTitleTag("t123456")
+    assert not isTitleTag("S123456")
+    assert not isTitleTag("T12345A")
+    assert not isTitleTag("T1234567")
+
+    assert not isTitleTag("None")
+    assert not isTitleTag(None)
+    assert not isTitleTag("STUFF")
+
+# END Test testBaseCommon_IsTitleTag
+
+@pytest.mark.base
+def testBaseCommon_IsItemClass():
+    """Test the isItemClass function.
+    """
+    assert isItemClass("NO_CLASS")
+    assert isItemClass("NOVEL")
+    assert isItemClass("PLOT")
+    assert isItemClass("CHARACTER")
+    assert isItemClass("WORLD")
+    assert isItemClass("TIMELINE")
+    assert isItemClass("OBJECT")
+    assert isItemClass("ENTITY")
+    assert isItemClass("CUSTOM")
+    assert isItemClass("ARCHIVE")
+    assert isItemClass("TRASH")
+
+    assert not isItemClass("None")
+    assert not isItemClass(None)
+    assert not isItemClass("STUFF")
+
+# END Test testBaseCommon_IsItemClass
+
+@pytest.mark.base
+def testBaseCommon_IsItemType():
+    """Test the isItemType function.
+    """
+    assert isItemType("NO_TYPE")
+    assert isItemType("ROOT")
+    assert isItemType("FOLDER")
+    assert isItemType("FILE")
+    assert isItemType("TRASH")
+
+    assert not isItemType("None")
+    assert not isItemType(None)
+    assert not isItemType("STUFF")
+
+# END Test testBaseCommon_IsItemType
+
+@pytest.mark.base
+def testBaseCommon_IsItemLayout():
+    """Test the isItemLayout function.
+    """
+    assert isItemLayout("NO_LAYOUT")
+    assert isItemLayout("TITLE")
+    assert isItemLayout("BOOK")
+    assert isItemLayout("PAGE")
+    assert isItemLayout("PARTITION")
+    assert isItemLayout("UNNUMBERED")
+    assert isItemLayout("CHAPTER")
+    assert isItemLayout("SCENE")
+    assert isItemLayout("NOTE")
+
+    assert not isItemLayout("None")
+    assert not isItemLayout(None)
+    assert not isItemLayout("STUFF")
+
+# END Test testBaseCommon_IsItemLayout
+
 @pytest.mark.base
 def testBaseCommon_HexToInt():
     """Test the hexToInt function.