Hi there
I'm afraid I don't know what the category numbers mean - I haven't encountered them in my searches (or just not noticed!)
Usually people referred themselved to the workhouse. Being in the workhouse was considered to be an absolute last resort. I could be wrong, but I don't believe anyone else could refer a person to the workhouse. People were supposed to be there of their own free will and from what I understand, the workhouse could apply to family to cover the expense of inmates - certainly in the case of medical care. So I think if any family members were trying to wash their hands of their relatives, they wouldn't let it be known that they were associated with or hand any responsibility for inmates.
Saying that, when my g g grandparents and their children were in Edmonton workhouse, g g grandfather's brother and address was listed as next of kin. From what I had seen in the records, that seemed to be quite unusual.
In the case of workhouse infirmaries, these were often the only 'hospitals' that poor people could go to, so this was a bit different to being in the workhouse itself. In that case, someone might well be taken to the infirmary by their family or gone there themselves.
Hope that helps!
Louise