It may have to do with the sport of cricket, where the boundaries of play are marked by ropes or "lines". +5

"- guideline: Etymology From guide + line" http://en.wiktionary.org/wiki/guideline "- guide: Etymology Originated 1325–75 from the Middle English verb giden or noun gide, from the Old French verb guider or noun guide, from Old Provençal guida, from guidar, from Germanic, from Frankish (*witan, “to show the way”). Akin to Old English witan (“to know”); see Proto-Indo-European *weid-." http://en.wiktionary.org/wiki/guide "- line: Etymology From Middle English line, from Old English lÄ«ne (‘cable, hawser’), probably from Latin linea (‘linen thread, string, line’) or linum (‘flax, thread, linen, cable’) or a conflation of both of those words. The English word was influenced by the French ligne (‘line’), which derives from the same Latin word, linea." http://en.wiktionary.org/wiki/line ------- (ADDED: possible origin) ------- "Noun 1. guideline - a light line that is used in lettering to help align the letters line - a mark that is long relative to its width; "He drew a line on the chart" 2. guideline - a detailed plan or explanation to guide you in setting standards or determining a course of action; "the president said he had a road map for normalizing relations with Vietnam" road map plan, program, programme - a series of steps to be carried out or goals to be accomplished; "they drew up a six-step plan"; "they discussed plans for a new bond issue" counseling, counselling, guidance, counsel, direction - something that provides direction or advice as to a decision or course of action 3. guideline - a rule or principle that provides guidance to appropriate behavior guidepost, rule of thumb rule, regulation - a principle or condition that customarily governs behavior; "it was his rule to take a walk before breakfast"; "short haircuts were the regulation"" Source and further information: http://www.thefreedictionary.com/guideline It is possible that meaning 1 (a light line that is used in lettering) appeared first as a concrete meaning, literally "a line to guide you by writing" and that the other, more abstract meanings, appeared later.