diff --git a/doc/dtd/blocks.ent b/doc/dtd/blocks.ent
index 16114e7ec58488d0ad1bad5e6276bb919efa22c4..11e97840ef5f630576b1fab1d8ee54b643b43da1 100644
--- a/doc/dtd/blocks.ent
+++ b/doc/dtd/blocks.ent
@@ -1,4 +1,4 @@
-<?xml encoding='US-ASCII'?>
+<?xml encoding='ISO-8859-1'?>
 
 <!-- BLOCKS ENTITY -->
 <!ENTITY % blocks "p|note|ul|ol|gloss|table|source|anchor">
diff --git a/doc/dtd/book.dtd b/doc/dtd/book.dtd
index 3885cee19b7ea37c4b75be059bb65dce0d1262eb..e7ccbb27a09cfbb41f10d7de89fdfa3fb7ff8bae 100644
--- a/doc/dtd/book.dtd
+++ b/doc/dtd/book.dtd
@@ -1,4 +1,4 @@
-<?xml encoding='US-ASCII'?>
+<?xml encoding='ISO-8859-1'?>
 
 <!-- STYLEBOOK BOOK DTD -->
 
diff --git a/doc/dtd/changes.dtd b/doc/dtd/changes.dtd
index ea3a111acf4d088ea71ad7a01ae0bbcb77903c10..5957c063b45968987543702499a9481bf7cf3acd 100644
--- a/doc/dtd/changes.dtd
+++ b/doc/dtd/changes.dtd
@@ -1,4 +1,4 @@
-<?xml encoding='US-ASCII'?>
+<?xml encoding='ISO-8859-1'?>
 
 <!-- STYLEBOOK CHANGES DTD -->
 
diff --git a/doc/dtd/characters.ent b/doc/dtd/characters.ent
index 019fb6eb4ae036b2851f2c0435852253c3a38223..d3780e5f6a3023d9b2821bef7e2d2d9fdfd0e876 100644
--- a/doc/dtd/characters.ent
+++ b/doc/dtd/characters.ent
@@ -1,4 +1,4 @@
-<?xml encoding='US-ASCII'?>
+<?xml encoding='ISO-8859-1'?>
 
 <!-- CHARACTERS ENTITY -->
 
diff --git a/doc/dtd/document.dtd b/doc/dtd/document.dtd
index cebe5a6a42c550594572b328325ecf59d49cee6a..2358c5368d750c706388906c0f948bdcd682536d 100644
--- a/doc/dtd/document.dtd
+++ b/doc/dtd/document.dtd
@@ -1,4 +1,4 @@
-<?xml encoding='US-ASCII'?>
+<?xml encoding='ISO-8859-1'?>
 
 <!-- STYLEBOOK DOCUMENT DTD -->
 
diff --git a/doc/dtd/entities.ent b/doc/dtd/entities.ent
index 97a32e369de4c350f49e235bc62d3431b94952aa..d0bc673f563f66451cedbba215cb14b9f6863db8 100644
--- a/doc/dtd/entities.ent
+++ b/doc/dtd/entities.ent
@@ -1,4 +1,4 @@
-<?xml encoding="US-ASCII"?>
+<?xml encoding="ISO-8859-1"?>
 
 <!ENTITY XercesCFullName      "Xerces C++ Parser">            <!-- fullproductname -->
 <!ENTITY XercesCName          "Xerces-C">                     <!-- productname -->
diff --git a/doc/dtd/faqs.dtd b/doc/dtd/faqs.dtd
index df4d4b344dc8f64bbb3a2b1ad283fd9ed935d6e6..4a7e9998a3a273973abe0aa90b4fbf5bf430098a 100644
--- a/doc/dtd/faqs.dtd
+++ b/doc/dtd/faqs.dtd
@@ -1,4 +1,4 @@
-<?xml encoding='US-ASCII'?>
+<?xml encoding='ISO-8859-1'?>
 
 <!-- STYLEBOOK FAQS DTD -->
 
diff --git a/doc/dtd/links.ent b/doc/dtd/links.ent
index b6ccc07d6ce4bb417ee30db145e390a836f981db..a8f9fd494cea94416db4dbe239a7b6efdf9eba52 100644
--- a/doc/dtd/links.ent
+++ b/doc/dtd/links.ent
@@ -1,4 +1,4 @@
-<?xml encoding='US-ASCII'?>
+<?xml encoding='ISO-8859-1'?>
 
 <!-- LINKS ENTITY -->
 <!ENTITY % links "link|anchor|jump|img|resource-ref|human-resource-ref">
diff --git a/doc/dtd/markup.ent b/doc/dtd/markup.ent
index a82e0e74356eab7ef7cb62b3c8975c3685c34d9b..510713cfbad88137724fe422ee77771e6213ec38 100644
--- a/doc/dtd/markup.ent
+++ b/doc/dtd/markup.ent
@@ -1,4 +1,4 @@
-<?xml encoding='US-ASCII'?>
+<?xml encoding='ISO-8859-1'?>
 
 <!-- MARKUP ENTITY -->
 <!ENTITY % markup "em|ref|code|br">
diff --git a/doc/entities.ent b/doc/entities.ent
index 97a32e369de4c350f49e235bc62d3431b94952aa..d0bc673f563f66451cedbba215cb14b9f6863db8 100644
--- a/doc/entities.ent
+++ b/doc/entities.ent
@@ -1,4 +1,4 @@
-<?xml encoding="US-ASCII"?>
+<?xml encoding="ISO-8859-1"?>
 
 <!ENTITY XercesCFullName      "Xerces C++ Parser">            <!-- fullproductname -->
 <!ENTITY XercesCName          "Xerces-C">                     <!-- productname -->
diff --git a/samples/data/redirect.dtd b/samples/data/redirect.dtd
index 7732f02df403b6f90c1ab3f065176b241ccd3233..4ebe6655cc90c46a6b46696343d1479443da72d8 100644
--- a/samples/data/redirect.dtd
+++ b/samples/data/redirect.dtd
@@ -1,4 +1,4 @@
-<?xml encoding="US-ASCII"?>
+<?xml encoding="ISO-8859-1"?>
 
 <!-- @version: -->