The letter-spacing attribute controls spacing between text characters, in addition to any spacing from the kerning attribute.
If the attribute value is a unitless number (like 128), the browser processes it as a <length> in the current user coordinate system.
If the attribute value has a unit identifier, such as .25em or 1%, then the browser converts the <length> into its corresponding value in the current user coordinate system.
Note: As a presentation attribute, letter-spacing can be used as a CSS property. See the CSS letter-spacing property for more information.
You can use this attribute with the following SVG elements: