The slope attribute defines the values for linear filters, such as brightness.

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 transform attribute defines a list of transform definitions that are applied to an element and the element's children.

The JavaScript warning "unreachable code after return statement" occurs when using an expression after a return statement, or when using a semicolon-less return statement but including an expression directly after.

The vert-origin-y attribute indicates the y-coordinate in the font coordinate system of the origin of a glyph to be used when drawing vertically oriented text.

The unicode-bidi attribute specifies how the accumulation of the background image is managed.

The text-anchor attribute is used to align (start-, middle- or end-alignment) a string of pre-formatted text or auto-wrapped text where the wrapping area is determined from the inline-size property relative to a given point.

The JavaScript exception "missing = in const declaration" occurs when a const declaration was not given a value in the same statement (like const RED_FLAG;). You need to provide one (const RED_FLAG = "#ff0").

The x-height attribute indicates the height of lowercase glyphs in the font within the font coordinate system.

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.