**Recommendation M0 **

======Recommendation to use stable PID systems to refer to frequently used redundant metadata wherever possible======

=====Description=====

Status: ~~LASTMOD~~

=====Motivation for this Recommendation: =====

[shortened from below]

=====Recommendation ====

[shortened from below]

[Format: Wer! macht was! wo! wann! unter welchen Voraussetzungen!]

=====Binding Convention: =====


^                         ^ mandatory  ^ conditional	          ^ optional ^
^ Helmholtz FAIR Principle|            |      |          |

=====Precondition for Implementation: =====

=====Related Recommendations =====

Parent:

Dependent:

Other: none

=====Contributors=====

Names of contributors to this recommendation

=====Content=====

====1. Explanation of the Background and Benefits of the Recommendation ====

__About__

Defintion of PIDs
  * A persistent identifier (PI or PID) is a long-lasting reference to a document, file, web page, or other object (from Wikipedia).
  * PID registers typically store core metadata with the PID
  * PIDs are used in data infrastructures to link to common information 
  * Harmonizing the use of PIDs may improve interoperability of datasets between data repositories

Criteria for the evaluation of PID Systems

  - PID is globally unambiguously registerable
  - PIDs are widely used, e.g. recommended by national and international organizations
  - PID registrar has transparent governance
  - Handle system has stable funding
  - PID system is reliably available and maintained
  - PIDs have an adequate metadata set
  - PID registration is open to all (vs. paying users only)
  - PID is machine readable via API
  - Further developments are downward compatible (with previous updates, content and technical)
  - Also: What other PID systems capture the same types of data?



__History and structure__

__Current Use of ...__

__Motivation__

====2. Possible alternative solutions====

====3. Consideration of the advantages and disadvantages of implementing the recommendation====

(quality of content, limitations, interoperability, sustainability:
expected future dissemination / technical availability / funding)

====4. The Recommendation====

[Format: Wer! macht was! wo! wann! unter welchen Voraussetzungen!]

====5. Naming of communities that have already implemented the recommendation====

====6. Documentation of the test to validate correct implementation====



====7. Examples of Instances====

====8. Further Information====

===References===

===Relevant Community Recommendations===

====9. History of this document====