Square brackets [ ] where introduced in Fortran 2003 tob e used instead of (/ /) for array constructors.

In the following case 

-----------------begin math.f90
real(pReal), dimension(6), parameter, private :: &
   nrmMandel = [&
     1.0_pReal,                1.0_pReal,                1.0_pReal,&
     1.414213562373095_pReal,  1.414213562373095_pReal,  1.414213562373095_pReal ]   !< weighting for Mandel notation (forward)
-----------------end math.f90

they are not treated correctly. Doxygen finds two entities:

-----------------begin documentation
real(preal), dimension(6), parameter, public math::invnrmmandel = [ 1.0_pReal
real(preal), dimension(6), parameter, public math::_preal
-----------------end documentation

where pReal is a kind(precision) specification for real numbers

with old style brackets, it works perfectly fine, even with all the line breaks.

-----------------begin math.f90
real(pReal), dimension(6), parameter, private :: &
   nrmMandel = (/&
     1.0_pReal,                1.0_pReal,                1.0_pReal,&
     1.414213562373095_pReal,  1.414213562373095_pReal,  1.414213562373095_pReal /)   !< weighting for Mandel notation (forward)
-----------------end math.f90

-----------------begin documentation
real(preal), dimension(6), parameter, private math::nrmmandel = (/ 1.0_pReal, 1.0_pReal, 1.0_pReal, 1.414213562373095_pReal, 1.414213562373095_pReal, 1.414213562373095_pReal /)
-----------------end documentation


In case any help/examples/explanation is needed, please don't hesitate to ask me