Hi Marco,
the linkout program is not "a sort of reading tools", it's just a way to provide a link to the online article (if there is one), directly from the PubMed citation, via a customizable button.
What I mean by "a sort of reading tools" is that Linkout allows the publisher to provide links from the PubMed entry to multiple resources relating to the article, not just the original online source; eg. related definitions, non-expert terminology, thesauri, etc. This is heavily under-used in biomedical literature, but is much more common in Genbank entries, for example. So, most journal entries only point back to the online article, but some have additional links to Pubmed Central, etc.
It requires some data to be provided to the NIH FTP in XML format, in a way they can identify the citation, and link to the proper online resource.
Yes, and this format as far as I'm aware this is the
NLM Standard Publisher Data Format that is used to submit items to Pubmed/Medline. This is the format the OJS currently exports using the PubMed export plugin.
I know in one of my past posts, probably due to my poor english, I wrote a sentence in which it was not clear if I knew the difference between PubMed and PubMed Central. I pledged guilty at that time, now please do not assume every time I post something, I don't know what I'm talking about!
Let me clearly say that your English is excellent, and that I'm not making any assumptions whether you know what you're talking about -- quite the opposite, your posts are very insightful and informative. The only reason I raised the issue with PubMed and Pubmed Central is that it is an extremely common mix-up which is the result of NLM/NIH's very poor choice of naming convention. So, it has nothing to do with you at all.
Hope this helps,
MJ