I am struck by the use of "Magn Reson Mater Phy" as an abbreviation by the journal "Magnetic Resonance Materials in Physics, Biology and Medicine" (a.k.a. "MAGMA"). See [here][1] for an example.

Their [instructions for authors][2] say:

> In order to have all citations to the journal taken into account in
> the calculation of the Thomson-ISI impact factor and citation index,
> please always refer to MAGMA as Magn Reson Mater Phy in all your
> publications. Magn Reson Mater Phy is the only official abbreviation
> of the journal.

That use is of course reflected in the Web of Science.

On the same site, they say:

> Always use the standard abbreviation of a journal’s name according to
> the ISSN List of Title Word Abbreviations, see [ISSN.org LTWA][3].

Using the LTWA and ISO-4 rules, I determine "Magn Reson Mater Phys Biol Med" as an abbreviation; note "Biol Med" and the extra "s" in "Phys". "Physics = Phys." is even an explicit example in ISO-4 (section 3.5) and often used, for example, in the abbreviation of "Medical Physics" ("Med Phys").

So, I wonder why Springer says the "official abbreviation" is one that is different from the LTWA. Is that for historical reasons, and MAGMA just sticks to it because the ISI impact factor is so powerful? Is there are title history that I may have overlooked? Or is there another reason Springer uses a different abbreviation for "Physics" and omits everything after the comma? In the whole ISO-4, I have not found any indication to do anything like that.

**Update:**
A little bit of history. MAGMA was born as "MAGMA" in 1993 (with no explanation of the meaning in the [first editorial][4]). The [NML catalog][5] says that "Issues for Apr. 1994- have subtitle: Magnetic resonance materials in physics, biology, and medicine." So there is no indication of any title not involving "Biology and Medicine".

The header line read MAGMA in all papers until the end of 1997 ([see that year's last paper][6]), and had been changed to "Magnetic Resonance Materials in Physics, Biology and Medicine" in the [first editorial][7] after the publisher had changed to Elsevier in 1998. It remained like this until [issue 15][8], when the publisher changed to Springer; they started using "MAGMA" [again][9] until [issue 18][10]; since [issue 19][11], they have been using "Magn Reson Mater Phy" in the header line until today. Note that the [ISO-4 standard][12] has not changed since 1997.

Also, the Web of Science says in the JCR:

> **Titles** 
> 
> ISO: Magn. Reson. Mat. Phys. Biol. Med. 
> 
> JCR Abbrev: MAGN RESON MATER PHY

<strike>So there is no doubt the abbreviation I determined is correct.</strike> (Yes, there is! Note the difference in "Mater" [my abbreviation, according to LTWA] vs. "Mat" [ISO abbreviation according to JCR].) But still my question remains: Why does Springer/JCR use a different abbreviation? Who was the first to use it? And why do they still recommend using it?

  [1]: http://link.springer.com/article/10.1007/s10334-015-0506-3#page-1
  [2]: https://www.springer.com/medicine/radiology/journal/10334?print_view=true&detailsPage=pltci_1060896
  [3]: http://www.issn.org/services/online-services/access-to-the-ltwa/
  [4]: http://dx.doi.org/10.1007/BF02660365
  [5]: https://www.ncbi.nlm.nih.gov/nlmcatalog?term=%22MAGMA%22[Title%20Abbreviation]
  [6]: http://dx.doi.org/10.1007/BF02595047
  [7]: http://dx.doi.org/10.1007/BF02662504
  [8]: http://dx.doi.org/10.1007/BF02693844
  [9]: http://dx.doi.org/10.1007/s10334-003-0001-0
  [10]: http://dx.doi.org/10.1007/s10334-005-0021-z
  [11]: http://dx.doi.org/10.1007/s10334-005-0018-7
  [12]: http://www.iso.org/iso/home/store/catalogue_tc/catalogue_detail.htm?csnumber=3569