SVFR kind of makes sense, in class D you're not separated from IFR or vice versa, only traffic info.
Cloudwise class D restricts you to remain 1000ft from them vertically (added to this the normal 500ft above ground)
So, going closer to clouds, and removing the "time to respond"-buffer for an IFR flight comming out of clouds, they've added extra security in you need SVFR clearance.... and you'll be separated from IFR flights.
So in generel, if you want to go closer than 1000ft vertically to clouds, you need SVFR clearance, and you can always ask for one if going over cities/water/mountains etc... whether ATC will approve it.... is another matter
