A MEF file is simply a ZIP file which contains the following files:
metadata.xml: this file contains the metadata itself, in XML format. The text encoding of the metadata is that one specified into the XML declaration.
info.xml: this is a special XML file which contains information related to the metadata but that cannot be stored into it. Examples of such information are the creation date, the last change date, privileges on the metadata and so on. Now this information is related to the GeoNetwork’s architecture.
public: this is a directory used to store the metadata thumbnails and other public files. There are no restrictions on the images’ format but it is strongly recommended to use the portable network graphics (PNG), the JPEG or the GIF formats.
private: this is a directory used to store all data (maps, shape files etc...) associated to the metadata. Files in this directory are private in the sense that an authorisation is required to access them. There are no restrictions on the file types that can be stored into this directory.
Any other file or directory present into the MEF file should be ignored by readers that don’t recognise them. This allows actors to add custom extensions to the MEF file.
A MEF file can have empty public and private folders depending on the export format, which can be:
simple: both public and private are omitted.
partial: only public files are provided.
full: both public and private files are provided.
It is recommended to use the .mef extension when naming MEF files.