diff --git a/nw/constants/__init__.py b/nw/constants/__init__.py
index 1abd529c..57761e42 100644
--- a/nw/constants/__init__.py
+++ b/nw/constants/__init__.py
@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 from nw.constants.iso import isoLanguage, isoCountry
 from nw.constants.constants import (
-    nwConst, nwFiles, nwKeyWords, nwLabels, nwQuotes, nwUnicode
+    nwConst, nwRegEx, nwFiles, nwKeyWords, nwLabels, nwQuotes, nwUnicode
 )
 from nw.constants.enum import (
     nwAlert, nwDocAction, nwItemClass, nwItemLayout, nwItemType, nwOutline
@@ -11,6 +11,7 @@ __all__ = [
     "isoLanguage",
     "isoCountry",
     "nwConst",
+    "nwRegEx",
     "nwFiles",
     "nwKeyWords",
     "nwLabels",
diff --git a/nw/constants/constants.py b/nw/constants/constants.py
index 66b026fc..5c483657 100644
--- a/nw/constants/constants.py
+++ b/nw/constants/constants.py
@@ -34,6 +34,14 @@ class nwConst():
 
 # END Class nwConst
 
+class nwRegEx():
+
+    FMT_B  = r"(?<![\w|\*|_|\\])([\*|_]{2})(?!\s|\*|_)(.+?)(?<![\s|\\])(\1)(?!\w)"
+    FMT_I  = r"(?<![\w|\*|_|\\])([\*|_])(?!\s|\*|_)(.+?)(?<![\s|\\])(\1)(?!\w)"
+    FMT_BI = r"(?<![\w|\*|\\])([\*]{3})(?!\s|\*)(.+?)(?<![\s|\\])(\1)(?!\w)"
+
+# END Class nwRegEx
+
 class nwFiles():
 
     PROJ_FILE   = "nwProject.nwx"
diff --git a/nw/gui/dochighlight.py b/nw/gui/dochighlight.py
index 376f779e..e81d9bca 100644
--- a/nw/gui/dochighlight.py
+++ b/nw/gui/dochighlight.py
@@ -33,7 +33,7 @@ from PyQt5.QtGui import (
     QColor, QTextCharFormat, QFont, QSyntaxHighlighter, QBrush
 )
 
-from nw.constants import nwUnicode
+from nw.constants import nwUnicode, nwRegEx
 
 logger = logging.getLogger(__name__)
 
@@ -140,21 +140,21 @@ class GuiDocHighlighter(QSyntaxHighlighter):
 
         # Markdown
         self.hRules.append((
-            r"(?<![\w|\*|\\])([\*])(?!\s|\1)(.+?)(?<![\s|\\])(\1)(?!\w)", {
+            nwRegEx.FMT_I, {
                 1 : self.hStyles["hidden"],
                 2 : self.hStyles["italic"],
                 3 : self.hStyles["hidden"],
             }
         ))
         self.hRules.append((
-            r"(?<![\w|\*|\\])([\*]{2})(?!\s|\*)(.+?)(?<![\s|\\])(\1)(?!\w)", {
+            nwRegEx.FMT_B, {
                 1 : self.hStyles["hidden"],
                 2 : self.hStyles["bold"],
                 3 : self.hStyles["hidden"],
             }
         ))
         self.hRules.append((
-            r"(?<![\w|\*|\\])([\*]{3})(?!\s|\*)(.+?)(?<![\s|\\])(\1)(?!\w)", {
+            nwRegEx.FMT_BI, {
                 1 : self.hStyles["hidden"],
                 2 : self.hStyles["bolditalic"],
                 3 : self.hStyles["hidden"],