High Quality Content by WIKIPEDIA articles! X logical font description (XLFD) is a font standard used by the X Window System. One prominent XLFD convention is to refer to individual fonts including any variations using their unique FontName. A technical standard is an established norm or requirement. It is usually a formal document that establishes uniform engineering or technical criteria, methods, processes and practices. In contrast, a custom, convention, company product, corporate standard, etc. which becomes generally accepted and dominant is often called a de facto standard. A technical standard can also be a controlled artifact or similar formal means used for calibration.