How long is a DOI?

In 2024 DataCite released their first public data file. It&rsquo;s easy to get a copy . Crossref have made a data dump available for the past few years. &#xA; Having both files available opens up some interesting possibilities in comparing and combining the two data sources. &#xA; The most obvious place to look is the DOIs themselves&hellip; &#xA; &hellip; and the simplest question you could ask…