Doh.

ISHelp/isxfunc.xml

@@ -1837,7 +1837,7 @@ end;</pre>
       <function>
         <name>Extract7ZipFile</name>
         <prototype>function Extract7ZipFile(const FileName, DestDir: String; const FullPaths: Boolean): Integer;</prototype>
-        <description><p>Extracts the specified 7-Zip archive to the specified directory, with or without using path names. Returns zero if successful, zero otherwise.</p></description>
+        <description><p>Extracts the specified 7-Zip archive to the specified directory, with or without using path names. Returns zero if successful, nonzero otherwise.</p></description>
         <remarks><p>Uses an embedded version of the &quot;7z ANSI-C Decoder&quot; from the LZMA SDK by Igor Pavlov, as-is, except that Unicode support was improved.</p>
 <p>All output of the decoder is logged if logging is enabled, including error messages but excluding empty lines.</p>
 <p>The decoder has the following limitations, as written by Igor Pavlov in file 7zC.txt of the LZMA SDK:<br /><br />