Digital Object Identifiers (DOIs) represent a key way to link your eBooks and other resources to external catalogues for the long term, and they are now a standard part of a typical bibliographic reference, especially where the reference is to a work accessed online. Typically you will file links to your resources with an organisation such as CrossRef, who in return will issue you with a corresponding list of DOI names (or just "DOIs" for short); these are in a format such as:
These DOIs can be used alone, but only if the reader has access to a link resolver. It is more convenient (and is the standard for some citation formats including APA) to include a link to the DOI.org link resolver, for example as follows:
Visiting this URL automatically redirects to the original resource, in this case a paper published by the American Psychological Association. However simply visiting https://dx.doi.org presents the user with an input box; pasting in the DOI name will cause the redirect to happen as if the user had visited the combined URL, hence it is more convenient.
DOIs in CloudPublish
DOIs in CloudPublish are simply added within your metadata. In ONIX 3.0 this is achieved by specifing the ProductIDType as 06 within a ProductIdentifier element.
Important note: You should provide the DOI name only in your metadata and not the link resolver URL, because the link resolver URL will be added automatically by CloudPublish where it is needed (e.g. for APA-style citations, but not for AMA or MLA which recommend giving the DOI name only).