diff --git a/chapter06/groff-exp.xml b/chapter06/groff-exp.xml
new file mode 100644
index 000000000..c8a35b947
--- /dev/null
+++ b/chapter06/groff-exp.xml
@@ -0,0 +1,13 @@
+
+Command explanations
+
+
+CXXFLAGS=-Dstrerror=strerror: If no macro
+strerror is defined, src/include/lib.h declares an function prototype
+for strerror which is incompatible with Glibc's /usr/include/string.h.
+By defining strerror=strerror a macro is defined which prevents the
+declaration and does not alter the meaning of strerror.
+
+
+
+
diff --git a/chapter06/groff.xml b/chapter06/groff.xml
index e0698e28a..393a03a97 100644
--- a/chapter06/groff.xml
+++ b/chapter06/groff.xml
@@ -2,6 +2,7 @@
Installing Groff
&c6-groff-inst;
+&c6-groff-exp;
&aa-groff-desc;
diff --git a/index.xml b/index.xml
index fb40d56e7..877df00eb 100644
--- a/index.xml
+++ b/index.xml
@@ -245,6 +245,7 @@
+