With the help of a Persistent Identifier (PID), a digital object remains sustainably and reliably accessible via a single fixed reference. Even if the website, URL structure, or technical infrastructure changes in the future, the PID continues to point to the correct object.

Persistent Identifiers form an important part of sustainable digital collection management and help organizations prevent so-called link rot: situations where hyperlinks no longer work because the underlying URL has changed or disappeared.


Why use a PID?
Web addresses can change over time. For example, when:

• A website is being updated.
• An object is being moved to another location.
• The URL structure is being adjusted.
• A collection migrates to another system.

When a regular URL changes, existing redirects no longer work.

A PID solves this problem because the URL itself is not used as a permanent reference, but rather a unique identifier that always points to the current location of the object.

As a result, the following remain:

• Publications
• Research reports
• Websites
• Linked Open Data
• Dataset registers
• External references

also function correctly in the long term.


What is a Persistent Identifier?
A Persistent Identifier (PID) is a unique and permanent identification code for a digital object, document, description, or dataset.

A PID does not refer directly to a web address, but to a record within a resolver system that knows where the object is located.

A PID typically consists of three parts:

1. Resolver
2. Prefix
3. Suffix

Example: https://hdl.handle.net/12345/6789

Whereby:

• https://hdl.handle.net is the resolver.
• 12345 is the prefix of the organization.
• 6789 is the unique identification of the object.

How does a PID work?
When someone opens a PID:

• The PID is submitted to a resolver.
• The resolver looks up the current location of the object.
• The user is automatically redirected to the correct page.

As a result, the same PID remains usable, even when the object is moved to a different URL behind the scenes.


PIDs within KLEKSI
KLEKSI supports the automatic generation and management of Persistent Identifiers.

This may involve use of:

• The standard PID functionality of KLEKSI.
• The internationally recognized Handle System.
• Existing Handle.net implementations in your organization.

After configuration, existing and future objects automatically receive a unique PID.

This PID remains linked to the object throughout the entire lifecycle of the registration.


Working with Handle.net
Organizations using the international Handle System require their own Handle prefix.

After receiving this prefix, KLEKSI can be linked to your Handle environment.

Then:

• KLEKSI configures the connection with Handle.
• Are the required PID registrations created automatically?
• Existing and new objects automatically receive a PID.
• Are changes to locations updated automatically?

As a result, every PID continues to correctly refer to the right object.

Retain existing PIDs
Are you already using Handle.net or another PID implementation?

Existing PIDs can then be transferred during a migration to KLEKSI.

As a result:

• Do existing links continue to work?
• Previously published PIDs will not be lost.
• Researchers and users do not need to use new links.

This is particularly important for organizations that have already published references in:

• Research reports
• Websites
• Heritage portals
• Dataset registers
• Linked Open Data Networks

PIDs and Linked Open Data
Persistent Identifiers form an important building block for Linked Open Data (LOD).

Because each object has a unique and stable identification:

• Can datasets be reliably linked?
• Do referrals remain valid for a long period?
• Can external systems uniquely identify objects?
• Is the exchangeability of collection data improved.

As a result, PIDs are essential for sustainable digital heritage registration.


Benefits of PIDs
The use of Persistent Identifiers offers several advantages:

• Durable and stable references to objects.
• Protection against link rot.
• Improved data exchangeability.
• Suitable for Linked Open Data.
• Support for international standards.
• Easier management of digital collections.
• Long-term accessibility of object information.

Important
A Persistent Identifier does not point to a specific URL, but to an object. As a result, the reference remains usable, even when the technical location of the object changes.

By using PIDs, you ensure that objects within your collection remain reliably findable, citable, and accessible to researchers, heritage institutions, and other users in the long term.