Field help (AOEFILEXT) 

It is used to define the path of a default data file that will be proposed during the launch of the import or export (and used in automatic fashion when launching an import or export chain). This file path can be relative, in this case, the database directory is supposed to be the database directory for the installation of the software).

The path can include the character #. If this is the case, there will be a sequential number management :

For instance, if the export sequence number is equal to 156, /u/tmp/fil# makes it possible to generate the /u/tmp/fil156 file.