According to the Curator Guide:
Note that there are a few uncommon situations where duplicate common names are ok, e.g. in situations where a species or subspecies really has a synonymous common name somewhere else.
In situations where it is clearly established in outside sources that a nominate subspecies really legitimately shares the same name as its parent species (such as the case with Trioceros jacksonii) then it seems like that is permissible to include.
Otherwise, it may be best to leave the name blank if no legitimate common name exists.