Prerequisite: Before you make PIDs which are globally resolvable you need to have a webpage for every item within your collection (see: How to implement human-readable PIDs).

A globally resolvable PID is one where there is a single globally accessible domain that turns the identifier into a link, and that single domain will work for all PIDs of that given type, without knowing which organisation created it. For example ‘https://doi.org/’ can be used to resolve any given DOI, no matter who created it. ‘https://n2t.net’ can resolve any ARK as long as it has been supplied and updated by the creator. Therefore PIDs that are globally resolvable are typically those with an internationally governed and supported community infrastructure.

By contrast, URIs require a user to know the full link including the domain including the country code in order to access the resources.

The National Gallery recently began assigning ARK identifiers to the paintings and entities within its collections. They took the identifiers already assigned to its collection and made them resolve using the N2T resolver. Some of these resolvers have a paid for element. The DOI implementations at the BL and NHM describe globally resolvable PIDs which are made possible via paid for third party services.

Effort

Some globally resolvable PID services such as DOIs have a cost associated with creating them, either through membership or per identifier. Others such as the N2T resolver are free to use to make your ARK resolvable. Third party human readable PIDs from external service providers will give you globally resolvable PIDs by default. The human resource effort involved in implementing globally resolvable PIDs is typically less than enabling resolution for in-house PIDs, because the resolution infrastructure already exists and can be used right away. Building a resolution service for a local PID implementation will require development and hosting, which will then have to be managed in perpetuity to support persistence. This can be done with relatively little financial commitment, but organisational commitment is equally required for both local and global resolution.