The marker-end attribute defines the arrowhead or polymarker that will be drawn at the final vertex of the given shape.

A block statement is used to group zero or more statements. The block is delimited by a pair of braces ("curly braces") and contains a list of zero or more statements and declarations.

The descent attribute defines the maximum unaccented depth of the font.

The textLength attribute, available on SVG <text> and <tspan> elements, lets you specify the width of the space into which the text will draw. The user agent will ensure that the text does not extend farther than that distance, using the method or methods specified by the lengthAdjust attribute. By default, only the spacing between characters is adjusted, but the glyph size can also be adjusted if you change lengthAdjust.

The maskUnits attribute indicates which coordinate system to use for the geometry properties of the <mask> element.

The min attribute specifies the minimum value of the active animation duration.

The JavaScript exception "invalid property name in regular expression" or "invalid class property name in regular expression" occurs when the \p and \P Unicode character class escapes are not followed by a valid Unicode property name and/or value.

The JavaScript exception "missing ) after condition" occurs when there is an error with how an if condition is written. It must appear in parenthesis after the if keyword.

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.

The requiredFeatures attribute takes a list of feature strings, with the individual strings separated by white space. It determines whether or not all of the named features are supported by the browser; if all of them are supported, the attribute evaluates to true end the element is rendered; otherwise, the attribute evaluates to false and the current element and its children are skipped and thus will not be rendered. This provides a way to design SVG that gracefully falls back when features aren't available.