Could you cite a few occurrences with at least the whole sentence as a context? If the form is as one sees in vṛkṣa-viśeṣa, niyama-viśeṣa (or vṛkṣāṇāṁ viśeṣaḥ, niyamānāṁ viśeṣaḥ etc., then viśeṣa has not been used in any unusual sense. 


On Oct 8, 2015, at 5:01 AM, Martin Gansten <martin.gansten@PBHOME.SE> wrote:

Balabhadra in his astrological work Hāyanaratna repeatedly makes use of the noun viśeṣa in a sense which seems from the context to mean something like ‘special rule' or 'part)icular consideration'. I haven't found this precise meaning in any dictionary and am curious to know if the term occurs with this technical meaning in any other śāstras.