Scholarly metadata, deposited by thousands of our members and made openly available can act as “trust signals” for the publications. It provides information that helps others in the community to verify and assess the integrity of the work. Despite having a central responsibility in ensuring the integrity of the work that they publish, editorial teams tend not be fully aware of the value of metadata for integrity of the scholarly record. How can we change that?
Crossref was created back in 2000 by 12 forward-thinking scholarly publishers from North America and Europe, and by 2002, these members had registered 4 million DOI records. At the time of writing, we have over 23,600 members in 164 different countries. Half of our members are based in Asia, and 35% are universities or scholar-led. These members have registered over 176 million open metadata records with DOIs (as of today). What a difference 25 years makes!
In our 25th anniversary year, I thought it would be time to take a look at how we got here. And so—hold tight—we’re going to go on an adventure through space and time1, stopping every 5 years through Crossref history to check in on our members. And we’re going to see some really interesting changes over the years.
The Frankfurt Book Fair is the largest book fair in the world, and therefore a key event on our calendar. Held annually in Frankfurt, Germany, the 77th Frankfurt Book Fair (October 15–19, 2025) saw 118,000 trade visitors and 120,000 private visitors from 131 countries. The Crossref booth was located, as usual, in Hall 4.0 where all the stands with information about academic publishing can be found. Four Crossref colleagues attended the Book Fair this year, and in this blog post, you can read more about their meetings, experiences, and plans.
TL;DR. Metadata Manager will be retired at the end of 2025. Over the past four years, we have been developing a new helper tool to replace it, and that tool has now reached a stage of maturity that means we will be able to switch off Metadata Manager by the end of the year.
We believe in Persistent Identifiers. We believe in defence in depth. Today we’re excited to announce an upgrade to our data resilience strategy.
Defence in depth means layers of security and resilience, and that means layers of backups. For some years now, our last line of defence has been a reliable, tried-and-tested technology. One that’s been around for a while. Yes, I’m talking about the humble 5¼ inch floppy disk.
This may come as surprise to some. When things go well, you’re probably never aware of them. In day to day use, the only time a typical Crossref user sees a floppy disk is when they click ‘save’ (yes, some journals still require submissions in Microsoft Word).
History
But why?
Let me take you back to the early days of Crossref. The technology scene was different. This data was too important to trust to new and unproven technologies like Zip disks, CD-Rs or USB Thumb Drives. So we started with punched cards.
IBM 5081-style punched card.
Punched cards are reliable and durable as long as you don’t fold, spindle or mutilate them. But even in 2001 we knew that punched cards’ days were numbered. The capacity of 80 characters kept DOIs short. Translating DOIs into EBCDIC made ASCII a challenge, let alone SICIs. We kept a close eye on the nascent Unicode.
Breathing Room
In 2017 the change of DOI display guidelines from http://dx.doi.org to https://doi.org shortened each DOI by 2 characters, buying us some time. But eventually we knew we had to upgrade to something more modern.
So we migrated to 5¼ inch floppy disks.
5¼ Floppy disk in drive
At 640 KB per disk these were a huge improvement. We could fit around 20,000 DOIs on one floppy. Today we only need around 10,000 floppy disks to store all of our DOIs (not the metadata, just the DOIs). Surprisingly this only takes about 20 metres of shelf space to store.
Typical work from home setup. Getting ready to backup some DOIs!
The move to working-from-home brought an unexpected benefit. Staff mail floppy disks to each other and keep them in constant rotation, which produces a distributed fault tolerant system.
Persistence Means Change
But it can’t last forever. DOIs registration shows no sign of slowing down. It’s clear we need a new, compact storage medium. So, after months of research, we’ve invested in new equipment.
Today we announce our migration to 3½ inch floppies.
If it goes to plan you won’t even notice the change.
