diff --git a/library/HTMLPurifier/ConfigSchema/Attr.IDBlacklistRegexp.txt b/library/HTMLPurifier/ConfigSchema/Attr.IDBlacklistRegexp.txt
index 5fa6a728..98f7c5a6 100644
--- a/library/HTMLPurifier/ConfigSchema/Attr.IDBlacklistRegexp.txt
+++ b/library/HTMLPurifier/ConfigSchema/Attr.IDBlacklistRegexp.txt
@@ -1,5 +1,5 @@
Attr.IDBlacklistRegexp
-TYPE: string
+TYPE: string/null
VERSION: 1.6.0
DEFAULT: NULL
--DESCRIPTION--
diff --git a/library/HTMLPurifier/ConfigSchema/Cache.DefinitionImpl.txt b/library/HTMLPurifier/ConfigSchema/Cache.DefinitionImpl.txt
index 65a88fed..e9fa699a 100644
--- a/library/HTMLPurifier/ConfigSchema/Cache.DefinitionImpl.txt
+++ b/library/HTMLPurifier/ConfigSchema/Cache.DefinitionImpl.txt
@@ -1,5 +1,5 @@
Cache.DefinitionImpl
-TYPE: string
+TYPE: string/null
VERSION: 2.0.0
DEFAULT: 'Serializer'
--DESCRIPTION--
diff --git a/library/HTMLPurifier/ConfigSchema/Cache.SerializerPath.txt b/library/HTMLPurifier/ConfigSchema/Cache.SerializerPath.txt
index 77a7766d..3682cbb3 100644
--- a/library/HTMLPurifier/ConfigSchema/Cache.SerializerPath.txt
+++ b/library/HTMLPurifier/ConfigSchema/Cache.SerializerPath.txt
@@ -1,5 +1,5 @@
Cache.SerializerPath
-TYPE: string
+TYPE: string/null
VERSION: 2.0.0
DEFAULT: NULL
--DESCRIPTION--
diff --git a/library/HTMLPurifier/ConfigSchema/Core.LexerImpl.txt b/library/HTMLPurifier/ConfigSchema/Core.LexerImpl.txt
index 100f8d1e..62125a47 100644
--- a/library/HTMLPurifier/ConfigSchema/Core.LexerImpl.txt
+++ b/library/HTMLPurifier/ConfigSchema/Core.LexerImpl.txt
@@ -1,5 +1,5 @@
Core.LexerImpl
-TYPE: mixed
+TYPE: mixed/null
VERSION: 2.0.0
DEFAULT: NULL
--DESCRIPTION--
diff --git a/library/HTMLPurifier/ConfigSchema/Core.MaintainLineNumbers.txt b/library/HTMLPurifier/ConfigSchema/Core.MaintainLineNumbers.txt
index 3a03ae74..de10208f 100644
--- a/library/HTMLPurifier/ConfigSchema/Core.MaintainLineNumbers.txt
+++ b/library/HTMLPurifier/ConfigSchema/Core.MaintainLineNumbers.txt
@@ -1,5 +1,5 @@
Core.MaintainLineNumbers
-TYPE: bool
+TYPE: bool/null
VERSION: 2.0.0
DEFAULT: NULL
--DESCRIPTION--
diff --git a/library/HTMLPurifier/ConfigSchema/Core.RemoveScriptContents.txt b/library/HTMLPurifier/ConfigSchema/Core.RemoveScriptContents.txt
index 8cc977c7..069d2537 100644
--- a/library/HTMLPurifier/ConfigSchema/Core.RemoveScriptContents.txt
+++ b/library/HTMLPurifier/ConfigSchema/Core.RemoveScriptContents.txt
@@ -1,5 +1,5 @@
Core.RemoveScriptContents
-TYPE: bool
+TYPE: bool/null
DEFAULT: NULL
VERSION: 2.0.0
DEPRECATED-VERSION: 2.1.0
diff --git a/library/HTMLPurifier/ConfigSchema/HTML.Allowed.txt b/library/HTMLPurifier/ConfigSchema/HTML.Allowed.txt
index 4b84a3a7..9329eb15 100644
--- a/library/HTMLPurifier/ConfigSchema/HTML.Allowed.txt
+++ b/library/HTMLPurifier/ConfigSchema/HTML.Allowed.txt
@@ -1,5 +1,5 @@
HTML.Allowed
-TYPE: itext
+TYPE: itext/null
VERSION: 2.0.0
DEFAULT: NULL
--DESCRIPTION--
diff --git a/library/HTMLPurifier/ConfigSchema/HTML.AllowedAttributes.txt b/library/HTMLPurifier/ConfigSchema/HTML.AllowedAttributes.txt
index 58e6137f..6ff12fc5 100644
--- a/library/HTMLPurifier/ConfigSchema/HTML.AllowedAttributes.txt
+++ b/library/HTMLPurifier/ConfigSchema/HTML.AllowedAttributes.txt
@@ -1,5 +1,5 @@
HTML.AllowedAttributes
-TYPE: lookup
+TYPE: lookup/null
VERSION: 1.3.0
DEFAULT: NULL
--DESCRIPTION--
diff --git a/library/HTMLPurifier/ConfigSchema/HTML.AllowedElements.txt b/library/HTMLPurifier/ConfigSchema/HTML.AllowedElements.txt
index c6cff7cd..04cbe2cc 100644
--- a/library/HTMLPurifier/ConfigSchema/HTML.AllowedElements.txt
+++ b/library/HTMLPurifier/ConfigSchema/HTML.AllowedElements.txt
@@ -1,5 +1,5 @@
HTML.AllowedElements
-TYPE: lookup
+TYPE: lookup/null
VERSION: 1.3.0
DEFAULT: NULL
--DESCRIPTION--
diff --git a/library/HTMLPurifier/ConfigSchema/HTML.AllowedModules.txt b/library/HTMLPurifier/ConfigSchema/HTML.AllowedModules.txt
index 59dc6f8d..7b8367e1 100644
--- a/library/HTMLPurifier/ConfigSchema/HTML.AllowedModules.txt
+++ b/library/HTMLPurifier/ConfigSchema/HTML.AllowedModules.txt
@@ -1,5 +1,5 @@
HTML.AllowedModules
-TYPE: lookup
+TYPE: lookup/null
VERSION: 2.0.0
DEFAULT: NULL
--DESCRIPTION--
diff --git a/library/HTMLPurifier/ConfigSchema/HTML.CustomDoctype.txt b/library/HTMLPurifier/ConfigSchema/HTML.CustomDoctype.txt
index 5edb6058..4b6d39cf 100644
--- a/library/HTMLPurifier/ConfigSchema/HTML.CustomDoctype.txt
+++ b/library/HTMLPurifier/ConfigSchema/HTML.CustomDoctype.txt
@@ -1,5 +1,5 @@
HTML.CustomDoctype
-TYPE: string
+TYPE: string/null
VERSION: 2.0.1
DEFAULT: NULL
--DESCRIPTION--
diff --git a/library/HTMLPurifier/ConfigSchema/HTML.DefinitionID.txt b/library/HTMLPurifier/ConfigSchema/HTML.DefinitionID.txt
index d3020e0c..07f6b67c 100644
--- a/library/HTMLPurifier/ConfigSchema/HTML.DefinitionID.txt
+++ b/library/HTMLPurifier/ConfigSchema/HTML.DefinitionID.txt
@@ -1,5 +1,5 @@
HTML.DefinitionID
-TYPE: string
+TYPE: string/null
DEFAULT: NULL
VERSION: 2.0.0
--DESCRIPTION--
diff --git a/library/HTMLPurifier/ConfigSchema/Output.Newline.txt b/library/HTMLPurifier/ConfigSchema/Output.Newline.txt
index ca8dfa97..20215725 100644
--- a/library/HTMLPurifier/ConfigSchema/Output.Newline.txt
+++ b/library/HTMLPurifier/ConfigSchema/Output.Newline.txt
@@ -1,5 +1,5 @@
Output.Newline
-TYPE: string
+TYPE: string/null
VERSION: 2.0.1
DEFAULT: NULL
--DESCRIPTION--
diff --git a/library/HTMLPurifier/ConfigSchema/URI.Base.txt b/library/HTMLPurifier/ConfigSchema/URI.Base.txt
index 505d6e34..a0f8d97b 100644
--- a/library/HTMLPurifier/ConfigSchema/URI.Base.txt
+++ b/library/HTMLPurifier/ConfigSchema/URI.Base.txt
@@ -1,5 +1,5 @@
URI.Base
-TYPE: string
+TYPE: string/null
VERSION: 2.1.0
DEFAULT: NULL
--DESCRIPTION--
diff --git a/library/HTMLPurifier/ConfigSchema/URI.DefinitionID.txt b/library/HTMLPurifier/ConfigSchema/URI.DefinitionID.txt
index 99b78fa5..20bfc1db 100644
--- a/library/HTMLPurifier/ConfigSchema/URI.DefinitionID.txt
+++ b/library/HTMLPurifier/ConfigSchema/URI.DefinitionID.txt
@@ -1,5 +1,5 @@
URI.DefinitionID
-TYPE: string
+TYPE: string/null
VERSION: 2.1.0
DEFAULT: NULL
--DESCRIPTION--
diff --git a/library/HTMLPurifier/ConfigSchema/URI.Host.txt b/library/HTMLPurifier/ConfigSchema/URI.Host.txt
index f782f7a0..15356ac2 100644
--- a/library/HTMLPurifier/ConfigSchema/URI.Host.txt
+++ b/library/HTMLPurifier/ConfigSchema/URI.Host.txt
@@ -1,5 +1,5 @@
URI.Host
-TYPE: string
+TYPE: string/null
VERSION: 1.2.0
DEFAULT: NULL
--DESCRIPTION--
diff --git a/library/HTMLPurifier/ConfigSchema/URI.Munge.txt b/library/HTMLPurifier/ConfigSchema/URI.Munge.txt
index 943c2093..b1207aab 100644
--- a/library/HTMLPurifier/ConfigSchema/URI.Munge.txt
+++ b/library/HTMLPurifier/ConfigSchema/URI.Munge.txt
@@ -1,5 +1,5 @@
URI.Munge
-TYPE: string
+TYPE: string/null
VERSION: 1.3.0
DEFAULT: NULL
--DESCRIPTION--