The units-per-em attribute specifies the number of coordinate units on the "em square", an abstract square whose height is the intended distance between lines of type in the same type size. This is the size of the design grid on which glyphs are laid out.

The string attribute is a hint to the user agent, and specifies a list of formats that the font referenced by the parent <font-face-uri> element supports.

The JavaScript exception "unparenthesized unary expression can't appear on the left-hand side of '**'" occurs when a unary operator (one of typeof, void, delete, await, !, ~, +, -) is used on the left operand of the exponentiation operator without parentheses.

The text-decoration attribute defines whether text is decorated with an underline, overline and/or strike-through. It is a shorthand for the text-decoration-line and text-decoration-style properties.

The scale attribute defines the displacement scale factor to be used on a <feDisplacementMap> filter primitive. The amount is expressed in the coordinate system established by the primitiveUnits attribute on the <filter> element.

The mode attribute defines the blending mode on the <feBlend> filter primitive.

The JavaScript exception "invalid assignment left-hand side" occurs when there was an unexpected assignment somewhere. It may be triggered when a single = sign was used instead of == or ===.

SVG supports the built-in XML xml:space attribute to handle whitespace characters inside elements. Child elements inside an element may also have an xml:space attribute that overrides the parent's one.

SVG makes use of a number of data types. This article lists these types along with their syntax and descriptions of what they're used for.

The JavaScript exception "missing name after . operator" occurs when there is a problem with how the dot operator (.) is used for property access.