[LibX] in Firefox 3.5 LibX is underlining phone number as if they were ISBN

Matthias Liffers matthias.liffers at gmail.com
Thu Jan 28 09:30:10 PST 2010

Hi Victoria (and list),

As far as I'm aware, LibX runs each 10-digit number it finds past a
little piece of code that sees if it follows the proper ISBN format.
Some technical information about this format is available:


There's at least one online utitlity that checks the numerical
validity of ISBNs. I've run both the numbers you've provided through
it, and they are both valid according to the numerical specification:


This is just unfortunate coincidence.  Every 10-digit number has a
chance of being valid according to ISBN standards, and some of your
phone numbers simply are.

I imagine it would be technically feasible to modify LibX so that it
checks every single numerically-valid 10-digit number against a
central database of ISBNs. This is probably not a very smart idea,
because the Internet isn't always very fast.

With tongue firmly in cheek, I suggest you change your phone numbers
to include either area codes or your country code so that they are no
longer 10 digits :-D


Matthias Liffers

2010/1/28 Victoria Lin <weilin at hulmail.harvard.edu>:
> Hi, we just noticed that when using Firefox 3.5, LibX is underlining some
> phone numbers in our staff directory because it thinks they are ISBN
> numbers. For example on
> http://hcl.harvard.edu/staff_directory/browse.cfm?ld_id=8
> 617-496-8294 and 617-495-2452 are underlined, while other phone numbers are
> not.
> our libx is version 1.5.13 rebuilt on Jan 25, 2010, I tested the old
> versions, happens there too. Could not replicate in IE.
> thanks,
> --
> Victoria Lin
> Systems Librarian
> Harvard University Library
> Office for Information Systems
> 90 Mt. Auburn St
> Cambridge, MA 02138
> Tel: 617-495-3724
> Email: weilin at hulmail.harvard.edu
> _______________________________________________
> Libx mailing list
> Libx at mozdev.org
> https://www.mozdev.org/mailman/listinfo/libx

More information about the Libx mailing list