As per my knowledge there is no set criteria for display of doi in the final PDF file. We can place it anywhere in the PDF as per suitability of the publisher. However, it should be on easy to read place so, it can attract the reader.
PDFs are mentioned below, but, like I said, we don’t have rigid guidelines for the location on or within a PDF:
An obligation of membership is that Crossref DOIs must be displayed on members’ response pages (also called landing pages). We recommend that Crossref DOIs also be displayed or distributed in the following contexts:
Tables of contents
Abstracts
Full text HTML and PDF articles, and other scholarly documents
Citation downloads to reference management systems
Metadata feeds to third parties
“How to Cite This” instructions on content pages
Social network links
Anywhere users are directed to a permanent, stable, or persistent link to the content
And, as a reminder, the guidelines are designed to meet these four goals:
To make it as easy as possible for users without technical knowledge to cut and paste or click to share Crossref DOIs (e.g. using right click to copy a URL).
To get users to recognize a Crossref DOI as both a persistent link as well as a persistent identifier, even if they don’t know what a DOI is.
To enable points 1 and 2 above by having all Crossref members display DOIs in a consistent way.
To enable robots and crawlers to recognize Crossref DOIs as URLs.
So, @Anjum’s recommendation is a good one! Thanks again!
Thank you for your detailed answer. Your answer created some new questions in my head, haha.
I’m familiar with the DOI display guidelines but on the list of recommendations you mention some itens that I never considered before:
Tables of contents
Abstracts
If you know about any journal that is already displaying DOI on Table of Contents and Abstracts, could you show me? I would like to have this example to copy and show others!
That was new for me, I’m constantly learning here:)