For what it's worth ... I'd suggest reconsidering getting him his own ... here's the reasons:
Legally the your permit - is YOUR permit ... that means that in order to use it, YOU have the be in the vehicle as well - every single time. If you aren't and someone finds out not only can YOU lose your permit (violation of terms of use) but also you and whoever is driving can be fined the same amount as if they didn't have the permit at all ($200-800 in many places). Keep in mind that the permit office links your permit number with your name and often drivers license (if applicable) .. so it's easy for parking authority/police etc to "find out" if they want to.
If your dad wants to go anywhere - with friends, family etc, having his own permit means that regardless of who is driving and what vehicle they take your dad is able to use a permit spot.
If you go out - aren't feeling well - any number of things this means that depending on how your dad is doing, he either has to:
a) stay home, because the parking might be a real issue (espeically street parking, malls at Christmas, various weather conditions etc).
b) Go out, but risk wearing himself out because of the distance he might have to walk etc .. which not only may physically be draining but is also emotionally difficult/frustrating
Also - most importantly, having his own permit allows him to retain his independence. He can come and go as he pleases, is able to go out without having you along (I'm sure you're great ... but everyone needs some time "with the guys/girls" etc).
If your family makes the choice not to get him a permit of his own ... please keep in mind that legally you are required by law then to be with him wherever he goes and uses the permit. If he uses your permit without you present, he's technically breaking the law - and you letting him use your permit without being present is a violation of your "terms of agreement" for having a HC permit ... if the permit dept finds out - you may have your permit taken back (at least temporarily) and you will likely have to pay a significant fine.
It just doesn't seem "worth it" to me ... please re-consider getting your Dad his own permit (provided the dr fills out the form naming your dad as the permit holder - in most cases a family member can handle the "getting of the permit" for your dad... if that makes a difference.
One thing that might help your dad accept the idea of the permit - is to think of it as an "Ability Permit" ... having the HC permit will give him the "Ability" to park in places that allow him to enjoy his life, enjoy his family, and do more, be more independent etc
![Smile :) :)](/community/styles/default/xenforo/smilies/smile.png)
Of course ... it might be worth playing the "Well dad, I have a HC permit... and it's doesn't make me feel ______ ... it just helps me be able to do what I want and need to do easier" card.