The glyphRef element provides a single possible glyph to the referencing <altGlyph> substitution.

The <foreignObject> SVG element includes elements from a different XML namespace. In the context of a browser, it is most likely (X)HTML.

The <feComponentTransfer> SVG filter primitive performs color-component-wise remapping of data for each pixel. It allows operations like brightness adjustment, contrast adjustment, color balance or thresholding.

The <feComposite> SVG filter primitive performs the combination of two input images pixel-wise in image space using one of the Porter-Duff compositing operations: over, in, atop, out, xor, lighter, or arithmetic.

The <feSpotLight> SVG filter primitive defines a light source that can be used to create a spotlight effect. It is used within a lighting filter primitive: <feDiffuseLighting> or <feSpecularLighting>.

The RegExp object is used for matching text with a pattern.

The <feTurbulence> SVG filter primitive creates an image using the Perlin turbulence function. It allows the synthesis of artificial textures like clouds or marble. The resulting image will fill the entire filter primitive subregion.

The <font-face-uri> SVG element points to a remote definition of the current font.

The comma (,) operator evaluates each of its operands (from left to right) and returns the value of the last operand. This is commonly used to provide multiple updaters to a for loop's afterthought.

Now that we covered the basics of the SVG internals, we will take a look at some tools to work with SVG files.