The font-size attribute refers to the size of the font from baseline to baseline when multiple lines of text are set solid in a multiline layout environment.

The from attribute indicates the initial value of the attribute that will be modified during the animation.

The font-stretch attribute indicates the desired amount of condensing or expansion in the glyphs used to render the text.

The end attribute defines an end value for the animation that can constrain the active duration.

The fill-opacity attribute is a presentation attribute defining the opacity of the paint server (color, gradient, pattern, etc.) applied to a shape.

The const declaration declares block-scoped local variables. The value of a constant can't be changed through reassignment using the assignment operator, but if a constant is an object, its properties can be added, updated, or removed.

The let declaration declares re-assignable, block-scoped local variables, optionally initializing each to a value.

The image-rendering attribute provides a hint to the browser about how to make speed vs. quality tradeoffs as it performs image processing.

The keyPoints attribute indicates the simple duration of an animation.

The gradientTransform attribute contains the definition of an optional additional transformation from the gradient coordinate system onto the target coordinate system (i.e., userSpaceOnUse or objectBoundingBox). This allows for things such as skewing the gradient. This additional transformation matrix is post-multiplied to (i.e., inserted to the right of) any previously defined transformations, including the implicit transformation necessary to convert from object bounding box units to user space.