This form can be accessed from the Document Configuration form, on the Groups tab.
Group - enter a unique name for the group.
Extension - enter the file extensions that are valid for this group (excluding the dot/point character). If you want to specify more than one extension they should be separated with a semi-colon.
It is acceptable that a file extension might be valid for more than one group.
Allow all extensions - enable this to allow files with any extension to be included in this group.