diff --git a/documentation/content/en/books/fdp-primer/editor-config/_index.adoc b/documentation/content/en/books/fdp-primer/editor-config/_index.adoc
--- a/documentation/content/en/books/fdp-primer/editor-config/_index.adoc
+++ b/documentation/content/en/books/fdp-primer/editor-config/_index.adoc
@@ -175,25 +175,6 @@
 
 Install from package:editors/emacs[] or package:editors/emacs-devel[].
 
-[[editor-config-emacs-validation]]
-=== Validation
-
-Emacs's nxml-mode uses compact relax NG schemas for validating XML.
-A compact relax NG schema for FreeBSD's extension to DocBook 5.0 is included in the documentation repository.
-To configure nxml-mode to validate using this schema, create [.filename]#~/.emacs.d/schema/schemas.xml# and add these lines to the file:
-
-[source,xml]
-.`~/.emacs.d/schema/schemas.xml`
-....
-<locatingRules xmlns="http://thaiopensource.com/ns/locating-rules/1.0">
-  <documentElement localName="section" typeId="DocBook" />
-  <documentElement localName="chapter" typeId="DocBook" />
-  <documentElement localName="article" typeId="DocBook" />
-  <documentElement localName="book" typeId="DocBook" />
-  <typeId id="DocBook" uri="/usr/local/share/xml/docbook/5.0/rng/docbook.rnc" />
-</locatingRules>
-....
-
 [[editor-config-emacs-igor]]
 === Automated Proofreading with Flycheck and Igor