What's the difference between proviso and provisor?

Proviso

Definition:

(n.) An article or clause in any statute, agreement, contract, grant, or other writing, by which a condition is introduced, usually beginning with the word provided; a conditional stipulation that affects an agreement, contract, law, grant, or the like; as, the contract was impaired by its proviso.

Example Sentences:

(1) No bit of the Human Rights Act, the European convention on human rights or the UN convention against torture has a proviso excluding foreigners with "funny" names or for those with the "wrong" ethnic or religious backgrounds.
(2) "The Conservative position on many aspects of policy therefore appeals more directly to this sense of stopping 'something for nothing'," Duffy said, adding a proviso that the extent of Tory support from the young shouldn't be exaggerated.
(3) The method does not rely upon the expression of the gene sequence of interest; the sole proviso is the availability of an appropriate DNA probe for the chromosomal region or locus of interest.
(4) But there is a proviso: the region's youth bulge came hand-in-hand with high-quality education that prepared a generation for the marketplace – as well as shrewd economic policies that widened that marketplace in the first place.
(5) In this respect, 1716 has prototype vaccine potential with the proviso that a direct extrapolation is being made from mouse to man.
(6) This is subject to a test of what is reasonable, and there is both a “heat of the moment” proviso and an honest mistake exception.
(7) The warning came as EDF unveiled plans to raise prices by 3.9% from January with a proviso – described as blackmail by critics – that the increase would be more if green taxes were not lifted by the government.
(8) the quality of the children is about the same with the proviso that the group is too small to conclude about the incidence of chromosomal abnormalities.
(9) With this proviso, a specific investigation scheme may be recommended.
(10) According to the exchange, Burton said: “As you know, although nominally under the auspices of the Liberal party lawyers’ professional branches, this is not a fundraiser – the cost charged is purely to cover dinner, including our guests and a small contingency for fixed costs in case of a numbers collapse … although of course people will disclose it if they go over the state donation limit.” Heydon’s personal assistant replied on Thursday at 9.23am and kept open the option of his attendance, with a proviso: “He does not wish to answer any questions after his address.
(11) With the proviso that the data may itself prove unreliable, Benetech's research nevertheless offers some useful clues about the makeup of the recorded death toll.
(12) Jakarta should become the priority for Australian prime ministers, he said, adding the proviso "barring things like international conferences that fall due on particular dates".
(13) Even the most accurate description will only be able to represent a part of the reality due to the proviso of only a limited view.
(14) A spokeswoman for Coe said: "Lord Coe did put his name forward on the proviso he wanted to consider if he had the capacity to do the role and if it was something that he wanted to take on.
(15) Cyprus suffered the biggest quarterly decline, shrinking by 0.8% (with the proviso that we only have annual data for Greece , where the economy is 3% smaller than a year ago ).
(16) In our experience, tissue expansion reconstruction offers distinct advantages in a large majority of patients with the proviso that patients are willing to accept the time required for hyperexpansion and the waiting period for deflation.
(17) Warm and generous in an interview that she was more or less arm-twisted into by her boss, Andrew Neil, Michel nevertheless has a proviso in doing so.
(18) The culture secretary, Jeremy Hunt, gave News Corp the green light to acquire the 60.9% of BSkyB it does not already own on Thursday – subject to a short public consultation that ends midday 8 July – on the proviso that Sky News is spun off as a separate company to allay plurality concerns.
(19) Ministers can simply choose who they feel is best for the job – the only proviso being that the prime minister must approve the appointment.
(20) The usual proviso applies -- US bonds are still being treated as extremely safe.