fgfgcfShow detail gcfgcfg
This happens with the identifier. It is basically just a GET parameter. The default value is "detailDceUid" but you may call it like you want. You should avoid to use a parameter name, which is already in use, like "id", "type" or "L", of course.
Now, when you call a page with a DCE on it and append the defined GET parameter to URL, you are able to trigger the detail template, instead of the "normal" one.
The value of the parameter must contain the uid of the content element itself (tt_content).
Lets say you have one page with three content elements, based on DCE (with uid=1, uid=2 and uid=3) and pass the GET param like this:
Show detail Bla bluubbb