From Forum Nokia Wiki

SVG profiles are subsets of SVG specification. It is usually because limitations of target devices where the SVG is used.

For mobile devices there are following profiles:

• • SVG Tiny (SVGT) or SVG Tiny 1.1

    SVG Tiny does not support gradients, transparency, clipping, masks,
    symbols,or SVG filter effects.

• • SVG Tiny 1.1 plus :-

    SVG Tiny 1.1 Plus includes the ability to display gradients and 
    transparency, but does not support clipping, masks, symbols, or SVG filter
    effects.

• • SVG Tiny 1.2 or SVG Basic (SVGB)

    SVG Basic does not support nonrectangular clipping or some SVG filter 
    effects.

External links:

http://www.w3.org/TR/SVGMobile/ -- Difference between SVGT and SVGB

http://wiki.svg.org/index.php?title=SVG_Tiny_1.1_Plus -- Differences among SVGT profiles