I think the subject says it all. Thank you in advance.

To be completely sure you should ask on the upload site of your choice for specific rules.
Here is a link to the FAQ/tutorial on planetelderscrolls : http://planetelderscrolls.gamespy.com/View.php?view=Tutorials.Detail&id=66
The main difference with other sites like Nexus is the colour of the "submit" button. I send exactly the same archive on both sites.