I don’t know if this is implemented in 3.x branch, but in 2.4.x there is no way to register a DOI for the journal… So I usually create and submit journal’s root DOIs by hand, that it’s not difficult, but kind of annoying doing a work that could be done by a machine. 
Here you have some info about “Journal level DOIs”:
May be it’s a nice addition for OJS 3.x?
Cheers,
m.
In OJS 3.X in settings of DOI plugin there are options as on screenshot below.
Is that what you suggest?
Thanks @vvucic. This is close, but it’s not what I’m asking for.
What I’m saying is that would be nice an additional check box called “Journal” that will create a permanent DOI to the root of the journal.
Let’s take this DOI pointing to an article… http://dx.doi.org/10.1594/PANGAEA.726855
The Journal’s DOI is: http://dx.doi.org/10.1594/PANGAEA
@bozana, do you think this is feasible and useful?
Cheers,
m.
Hi @marc
Yes, that could be done. This was/is not our priority, because nobody ever asked for it and it is only done once for a journal so that it is not so much manual work for the users. Any contribution is of course very welcome! Unfortunately, the code amount for that feature – to function in the same way as the DOIs are assigned and registered on the other levels and for different agencies – is not small, so that I am not sure if it is worth, but…
Best,
Bozana
Probably you are right and it’s too much code for a task that it’s done once or twice for each journal…
If I found time this week I will publish here a XML template that will also do the job.
Cheers,
m.
Sorry… I completely forget this.
Here you have an explanation about how to do this with CrossRef:
XML samples:
Replace with your data and submit to CrossRef via form. Piece of cake. 
