Mark fixes in second print in errata page

Author: marijnh

html/errata.html

@@ -21,21 +21,25 @@ <h1>Errata<div style="font-size: 70%"><a class="subtlelink" href="index.html">El
 page</a>. To report a problem that is not listed
 here, <a href="mailto:marijnh@gmail.com">send me an email</a>.</p>
 
+<p>Issues whose page number is followed by an ordinal number are only
+present up to the print denoted by that number. I.e. those followed by
+“1st” were fixed in the second print.</p>
 
 <h2>Chapter 2</h2>
 
-<p><strong>Page 34</strong> (Updating Bindings Succintly): Where it
+<p><strong>Page 34</strong> (1st) <em>Updating Bindings Succintly</em>: Where it
 says <code>counter-</code> it should be <code>counter--</code>.</p>
 
 <h2>Chapter 10</h2>
 
-<p><strong>Page 168</strong> (Modules as Building Blocks): In “each
+<p><strong>Page 168</strong> (1st) <em>Modules as Building Blocks</em>: In “each
 needs it own private scope“, it should say “<em>its</em> own private
 scope“.
 
 <h2>Chapter 20</h2>
 
-<p><strong>Page 369</strong> (Directory Creation): <code>MKCOL</code> stands for
-"make collection", not "make column" as the book claims.</p>
+<p><strong>Page 369</strong> (1st) <em>Directory
+Creation</em>: <code>MKCOL</code> stands for “make collection”, not “make
+column” as the book claims.</p>
 
 </article>