diff --git a/src/CLI.cpp b/src/CLI.cpp
index 1c5e71ccc..61bae23d2 100644
--- a/src/CLI.cpp
+++ b/src/CLI.cpp
@@ -33,6 +33,12 @@
 
 extern Context context;
 
+// Overridden by rc.abbreviation.minimum.
+static int minimumMatchLength = 3;
+
+// Alias expansion limit. Any more indicates some kind of error.
+static int safetyValveDefault = 10;
+
 ////////////////////////////////////////////////////////////////////////////////
 CLI::CLI ()
 : _program ("")
@@ -128,6 +134,43 @@ bool CLI::exactMatch (
   return false;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// Search for 'value' in _entities category, return canonicalized value.
+bool CLI::canonicalize (
+  std::string& canonicalized,
+  const std::string& category,
+  const std::string& value) const
+{
+  // Find the category.
+  std::pair <std::multimap <std::string, std::string>::const_iterator, std::multimap <std::string, std::string>::const_iterator> c;
+  c = _entities.equal_range (category);
+
+  // Extract a list of entities for category.
+  std::vector <std::string> options;
+  std::multimap <std::string, std::string>::const_iterator e;
+  for (e = c.first; e != c.second; ++e)
+  {
+    // Shortcut: if an exact match is found, success.
+    if (value == e->second)
+    {
+      canonicalized = value;
+      return true;
+    }
+
+    options.push_back (e->second);
+  }
+
+  // Match against the options, throw away results.
+  std::vector <std::string> matches;
+  if (autoComplete (value, options, matches, minimumMatchLength) == 1)
+  {
+    canonicalized = matches[0];
+    return true;
+  }
+
+  return false;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 void CLI::dump (const std::string& label) const
 {