diff --git a/src/SubstKeywords.py b/src/SubstKeywords.py
index 6bd63b4eb..a3a6aeb03 100644
--- a/src/SubstKeywords.py
+++ b/src/SubstKeywords.py
@@ -18,6 +18,21 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 #
 
+"""
+Provides the SubstKeywords class that will replace keywords in a passed
+string with informatin about the person. For sample:
+
+foo = SubstKeywords(person)
+print foo.replace('$n was born on $b.')
+
+Will return a value such as:
+
+Mary Smith was born on 3/28/1923.
+"""
+
+__author__ = "Donald N. Allingham"
+__version__ = "$Revision$"
+
 #------------------------------------------------------------------------
 #
 # python classes
@@ -31,14 +46,33 @@ import string
 #
 #------------------------------------------------------------------------
 class SubstKeywords:
+    """
+    Produces an object that will substitute information about a person
+    into a passed string.
+
+    $n -> Name - FirstName LastName
+    $N -> Name - LastName, FirstName
+    $i -> GRAMPS ID
+    $b -> Date of birth
+    $B -> Place of birth
+    $d -> Date of death
+    $D -> Place of death
+    $s -> Preferred spouse's name - FirstName LastName
+    $S -> Preferred spouse's name - LastName, FirstName
+    $m -> Date of preferred marriage
+    $M -> Place of preferred marriage
+    """
+    
     def __init__(self,person):
+        """Associates a person with the class"""
+
         self.n = person.getPrimaryName().getRegularName()
         self.N = person.getPrimaryName().getName()
         self.b = person.getBirth().getDate()
         self.d = person.getDeath().getDate()
         self.B = person.getBirth().getPlaceName()
         self.D = person.getDeath().getPlaceName()
-        self.i = "%s" % person.getId()
+        self.i = str(person.getId())
 
         if len(person.getFamilyList()) > 0:
             f = person.getFamilyList()[0]
@@ -61,6 +95,8 @@ class SubstKeywords:
             self.M = ""
 
     def replace(self,line):
+        """Returns a new line of text with the substitutions performed"""
+        
         line = string.replace(line,"$n",self.n)
         line = string.replace(line,"$N",self.N)
         line = string.replace(line,"$b",self.b)