On Mon, 28 May 2012, Patrick Häcker submitted the
autonum
package.
Summary description: Automatic number referenced equations License type: lppl
Announcement text: ----------------------------------------------------------------------
This is the autonum package, automatically numbering only the equations which are referenced. This package is similar to mathtools' showonlyrefs option, but without introducing the bug to overwrite long equations with the equation number.
----------------------------------------------------------------------
This package is located at http://mirror.ctan.org/macros/latex/contrib/autonum . More information is at http://www.ctan.org/pkg/autonum (if the package is new it may take a day for that information to appear). We are supported by the TeX Users Group http://www.tug.org . Please join a users group; see http://www.tug.org/usergroups.html .
------------------------------------------------------------------------
Thanks for the upload.
For the CTAN Team Rainer Schöpf