diff --git a/src/GamCommands.txt b/src/GamCommands.txt
index 9970bf22..00c9861a 100644
--- a/src/GamCommands.txt
+++ b/src/GamCommands.txt
@@ -43,6 +43,7 @@ If an item contains spaces, it should be surrounded by " or '.
 <DateTime> ::= <Year>-<Month>-<Day>(<Space>|T)<Hour>:<Minute>
 <Time> ::= <Year>-<Month>-<Day>(<Space>|T)<Hour>:<Minute>[:<Second>[.<MilliSeconds>[Z]]]
 <PrintJobAge> ::= <Number>(m|h|d)
+<REPattern> ::= <Python Regular Expression, see: https://docs.python.org/2/library/re.html>
 <UniqueID> ::= uid:<String>
 
 # Named items
@@ -680,7 +681,7 @@ gam <UserTypeEntity> deprovision|deprov
 gam <UserTypeEntity> [add] label|labels <Name> [messagelistvisibility hide|show] [labellistvisibility hide|show|showifunread]
 gam <UserTypeEntity> update labelsettings <LabelName> [name <Name>] [messagelistvisibility hide|show] [labellistvisibility hide|show|showifunread]
 gam <UserTypeEntity> update label|labels [search <PythonRegularExpression>] [replace <LabelReplacement>] [merge]
-gam <UserTypeEntity> delete|del label|labels <LabelName>|regex:<LabelREPattern>|--ALL_LABELS--
+gam <UserTypeEntity> delete|del label|labels <LabelName>|regex:<REPattern>|--ALL_LABELS--
 gam <UserTypeEntity> show labels|label [onlyuser] [showcounts]
 
 gam <UserTypeEntity> delete message|messages query <Query> [doit] [max_to_delete <Number>]
@@ -722,14 +723,15 @@ gam <UserTypeEntity> show sendas
 
 gam <UserTypeEntity> shortcuts <Boolean>
 
-gam <UserTypeEntity> signature|sig <String>|(file <FileName> [charset <Charset>])
+gam <UserTypeEntity> signature|sig <String>|(file <FileName> [charset <Charset>]) (replace <REPattern> <String>)*
 gam <UserTypeEntity> show signature|sig
 gam <UserTypeEntity> snippets <Boolean>
 
 gam <UserTypeEntity> utf|utf8|utf-8|unicode <Boolean>
 
 gam <UserTypeEntity> vacation <FalseValues>
-gam <UserTypeEntity> vacation <TrueValues> subject <String> (message <String>)|(file <FileName> [charset <CharSet>]) [contactsonly] [domainonly] [startdate <Date>] [enddate <Date>]
+gam <UserTypeEntity> vacation <TrueValues> subject <String> (message <String>)|(file <FileName> [charset <CharSet>]) (replace <REPattern> <String>)*
+	[contactsonly] [domainonly] [startdate <Date>] [enddate <Date>]
 gam <UserTypeEntity> show vacation
 
 gam <UserTypeEntity> webclips <Boolean>
diff --git a/src/gam.py b/src/gam.py
index 85d6daf1..4e8593f7 100755
--- a/src/gam.py
+++ b/src/gam.py
@@ -379,6 +379,32 @@ def getCharSet(i):
     return (i, GC_Values.get(GC_CHARSET, GM_Globals[GM_SYS_ENCODING]))
   return (i+2, sys.argv[i+1])
 
+def getREPattern(i):
+  if i < len(sys.argv):
+    patstr = sys.argv[i]
+    if patstr:
+      try:
+        pattern = re.compile(patstr)
+        return pattern
+      except re.error as e:
+        print u'ERROR: "{0}" is not a valid RE pattern: {1}'.format(patstr, e)
+        sys.exit(2)
+  print u'ERROR: expected an <REPattern>'
+  sys.exit(2)
+
+def getString(i, item, emptyOK=False, optional=False):
+  if i < len(sys.argv):
+    argstr = sys.argv[i]
+    if argstr:
+      return argstr
+    if emptyOK or optional:
+      return u''
+    print u'ERROR: expected a Non-empty <{0}>'.format(item)
+    sys.exit(2)
+  elif  optional:
+    return u''
+  print u'ERROR: expected a <{0}>'.format(item)
+  sys.exit(2)
 #
 # Open a file
 #
@@ -5062,19 +5088,24 @@ def getForward(users):
       pass
 
 def doSignature(users):
-  import cgi
   i = 4
   if sys.argv[i].lower() == u'file':
     filename = sys.argv[i+1]
     i += 2
     i, encoding = getCharSet(i)
-    signature = readFile(filename, encoding=encoding).replace(u'\\n', u'&#xA;').replace(u'\n', u'<br/>')
+    signature = readFile(filename, encoding=encoding).replace(u'\\n', u'<br/>').replace(u'\n', u'<br/>')
   else:
-    signature = cgi.escape(sys.argv[i]).replace(u'\\n', u'&#xA;').replace(u'"', u"'")
-  xmlsig = u'''<?xml version="1.0" encoding="utf-8"?>
-<atom:entry xmlns:atom="http://www.w3.org/2005/Atom" xmlns:apps="http://schemas.google.com/apps/2006">
-    <apps:property name="signature" value="%s" />
-</atom:entry>''' % signature
+    signature = getString(i, u'String', emptyOK=True).replace(u'\\n', u'<br/>').replace(u'\n', u'<br/>')
+    i += 1
+  while i < len(sys.argv):
+    if sys.argv[i].lower() == u'replace':
+      matchPattern = getREPattern(i+1)
+      matchReplacement = getString(i+2, u'String', emptyOK=True)
+      signature = matchPattern.sub(matchReplacement, signature)
+      i += 3
+    else:
+      print u'ERROR: %s is not a valid argument for "gam <users> signature"' % sys.argv[i]
+      sys.exit(2)
   emailsettings = getEmailSettingsObject()
   count = len(users)
   i = 1
@@ -5085,9 +5116,8 @@ def doSignature(users):
     else:
       emailsettings.domain = GC_Values[GC_DOMAIN] #make sure it's back at default domain
     print u"Setting Signature for %s (%s of %s)" % (user+u'@'+emailsettings.domain, i, count)
-    uri = u'https://apps-apis.google.com/a/feeds/emailsettings/2.0/%s/%s/signature' % (emailsettings.domain, user)
     i += 1
-    callGData(emailsettings, u'Put', soft_errors=True, data=xmlsig, uri=uri)
+    callGData(emailsettings, u'UpdateSignature', soft_errors=True, username=user, signature=signature)
 
 def getSignature(users):
   emailsettings = getEmailSettingsObject()
@@ -5161,6 +5191,11 @@ def doVacation(users):
       i += 2
       i, encoding = getCharSet(i)
       message = readFile(filename, encoding=encoding)
+    elif sys.argv[i].lower() == u'replace':
+      matchPattern = getREPattern(i+1)
+      matchReplacement = getString(i+2, u'String', emptyOK=True)
+      message = matchPattern.sub(matchReplacement, message)
+      i += 3
     else:
       print u'ERROR: %s is not a valid argument for "gam <users> vacation"' % sys.argv[i]
       sys.exit(2)
diff --git a/src/whatsnew.txt b/src/whatsnew.txt
index 692e9b16..69594eac 100644
--- a/src/whatsnew.txt
+++ b/src/whatsnew.txt
@@ -59,6 +59,13 @@ Added argument to `gam update group` to allow removing members by role.
 `gam update group <Group> clear [members] [managers] [owners]`
 If no option follows clear, all members will removed.
 
+Added argument to `gam <Users> signature` and `gam <Users> vacation` to allow pattern substitution in the signature and vacation message.
+`gam <Users> signature <String>|(file <FileName> [charset <Charset>]) (replace <REPattern> <String>)*`
+`gam <UserTypeEntity> vacation <TrueValues> subject <String> (message <String>)|(file <FileName> [charset <CharSet>]) (replace <REPattern> <String>)*
+	[contactsonly] [domainonly] [startdate <Date>] [enddate <Date>]`
+This is especially useful with CSV files.
+`gam csv Users.csv gam signature file SignatureTemplate.txt replace '#User#' '~User' replace '#Title#' '~Title'`
+
 Changed `gam print admins` to include 'id:' in OrgUnitID column as with other `gam print` commands.
 
 Fixed GAM to handle both future date error messages in `gam report`