Two formats are available for the delivery of metadata:
The MARC 21 field or the ONIX 3.0.8 tag is specified for each metadata element under "Metadata elements". Examples of the usage of individual fields in the respective format can also be found there.
The complete documentation of MARC 21 is available at https://www.loc.gov/marc/.
There are different communication format options for MARC 21. MARC 21 can be delivered either as a mrc file in accordance with ISO 2709 or as a MARCXML file.
The definition of the record structure in accordance with ISO 2709 as a mrc file is described at https://www.loc.gov/marc/specifications/specrecstruc.html. There are open source program libraries for creating and editing the mrc format in many programming languages (e.g. for Java, PERL, PHP, Python etc.). Some tools for generating and manipulating MARC 21 data are compiled by the Library of Congress at https://www.loc.gov/marc/marctools.html. The freeware tool MarcEdit is available under Windows, MacOS and Linux, with which MARC files can be read, validated and edited (see https://marcedit.reeset.net/).
The documentation, XSD and examples for MARCXML can be found at https://www.loc.gov/standards/marcxml/.
The complete documentation for ONIX for Books Release 3.0.8, the DTD and XSD are available at https://www.editeur.org/93/Release-3.0-Downloads/.
In ONIX format, tags can be specified in two options: as "Reference names" or "Short tags". EDItEUR provides an XSLT script at https://www.editeur.org/93/Release-3.0-Downloads/#Tools for converting "Reference names" into "Short tags" and vice versa.
UTF-8 must be used as the coded character set in the metadata deliveries. The character set must be declared in each metadata file.
In ONIX, the coded character set is specified in the encoding attribute of the XML declaration:
<?xml version="1.0" encoding="UTF-8"?>
In MARC 21, the coded character set is encoded in the leader, position 09. In MARCXML, as in ONIX, the character set is also specified in the XML declaration.
The data deliveries are preferably deposited via SFTP (Secure File Transfer Protocol) on a delivery account provided by the data recipient (library/library network head office). Alternatively, the data can be delivered using the OAI-PMH procedure (Open Archives Initiative Protocol for Metadata Harvesting).
If these delivery channels cannot be served by the delivering publisher/distributor, alternative delivery procedures must be agreed bilaterally with the library network head office/libraries.