" To me, additional needs could mean food, shelter, emotional support, nurturing; Anything under Maslow's hierarchy of needs I suppose."
I think that this must be a Scottish thing, tbh.
That top list gives what perennial responsibility is, so they are the rights of a child, not additional needs.
You need to look at this from a SS and the Children Act POV. A lot of the Charities and Providers given money under Children in Need, we're set up as services for Children In Need, under Section 17 of the 1989 Children Act, to further explain.
The definition given by "IAlways"
: having less money, education, etc., than the other people in a society : having fewer advantages, privileges, and opportunities than most people : poor or disadvantaged
Sums it up well, it isn't just about disadvantage. If you look at the Every Child Mayters agenda, then that explains it further.
The words used tie in with how Service Provision and the Laws and LA Policies are written.