Add @mbabker's example in

Author: wilsonge

manual/en-US/coding-standards/chapters/php.md

@@ -146,13 +146,23 @@ $ref1 = &$this->sql;
 > In PHP 5, reference operators are not required for objects. All objects are handled by reference.
 
 ## Concatenation Spacing
-There should always be a space between two objects for example
+There should always be a space before and after the concatenation operator ('.'). For example:
 
 ```php
 $id = 1;
 echo JRoute('index.php?option=com_foo&task=foo.edit&id=' . (int) $id);
 ```
 
+If the concatenation operator is the first or last character on a line, both spaces are not required. For example:
+
+```php
+$id = 1
+echo JRoute::_(
+    'index.php?option=com_foo&task=foo.edit&id=' . (int) $id
+    . '&layout=special'
+);
+```
+
 ## Arrays
 
 Assignments (the `=>` operator) in arrays may be aligned with tabs. When splitting array definitions onto several lines, the last value may also have a trailing comma. This is valid PHP syntax and helps to keep code diffs minimal.