collectionname!objectname' Use the exclamation point reference to refer to an object in a collection explicitly by its name.  This has the advantage of allowing you to refer to the object using a string expression that evaluates to the object's name.

collectionname("objectname")' Use the index by name reference to refer to an object in a collection explicitly by its name.  Similar to the former method, in that, you can create a string variable and use that for the object reference.

collectionname(index)' Use the index by number reference to refer to an object in a collection by the index number assigned to it.  [When you know the position number of an object in its collection, you can refer to the object using just the number.  Note:  Using a For Each. . . Next you can learn the position and/or name of an object in its collection!  Remember the collection is zero-based]  Looping through the collection is especially useful if turning a property (such as "Lock") on or off for all of the objects.

collectionname(objectvariable)' Use the index by variable reference to refer to an object in a collection by using a string variable to refer to the object.