diff --git a/source/intro.tex b/source/intro.tex
index 3e24d06dce..c4632c75a2 100644
--- a/source/intro.tex
+++ b/source/intro.tex
@@ -1066,6 +1066,12 @@
 published description, and explains in detail the differences between
 \Cpp{} and C\@. Certain features of \Cpp{} exist solely for compatibility
 purposes; \ref{depr} describes those features.
+
+\pnum
+\ref{uaxid} provides an outline of how \UAX{31}
+("Unicode Identifier and Pattern Syntax") has been applied to \Cpp{}.
+It provides a list of all requirements and whether they are enforced,
+guaranteed, or applicable to the standard.
 \indextext{standard!structure of|)}
 
 \rSec1[syntax]{Syntax notation}