Не отображался значёк рубля, поменял на glyphicon

abonapp/templates/abonapp/abonamount.html

@@ -15,7 +15,7 @@
                     <label for="amount">{% trans 'Amount of money' %}</label>
 
                     <div class="input-group">
-                        <span class="input-group-addon">&#8399;</span>
+                        <span class="input-group-addon"><span class="glyphicon glyphicon-ruble"></span></span>
                         <input id="amount" type="text" name="amount" placeholder="0.0" class="form-control" required
                                pattern="\d+">
                     </div>