read ▁ad option . ▁ ▁Pur pose ▁P erman ence ▁in ▁links ▁is ▁des irable ▁when ▁content ▁items ▁are ▁likely ▁to ▁be ▁linked ▁to , ▁from , ▁or ▁c ited ▁by ▁a ▁source ▁outside ▁the ▁origin ating ▁organization . ▁Before ▁the ▁advent ▁of ▁large - scale ▁dynamic ▁websites ▁built ▁on ▁database - back ed ▁content ▁management ▁systems , ▁it ▁was ▁more ▁common ▁for ▁URLs ▁of ▁specific ▁pieces ▁of ▁content ▁to ▁be ▁static ▁and ▁human ▁readable , ▁as ▁URL ▁structure ▁and ▁naming ▁were ▁dict ated ▁by ▁the ▁entity ▁creating ▁that ▁content . ▁In cre ased ▁volume ▁of ▁content ▁and ▁difficulty ▁of ▁management ▁led ▁to ▁the ▁rise ▁of ▁database - dri ven ▁systems , ▁and ▁the ▁resulting ▁unw ield y ▁and ▁often - ch anging ▁URLs ▁necess itated ▁deliber ate ▁policies ▁with ▁regard ▁to ▁URL ▁design ▁and ▁link ▁perman ence . ▁ ▁For ▁example , ▁Wikipedia ' s ▁internal ▁c gi - based ▁URLs ▁are ▁made ▁more ▁readable ▁by ▁simpl ifying ▁them . ▁The ▁internal ▁URI ▁for ▁a ▁Wikipedia ▁article ▁named ▁Example , ▁which ▁is ▁http :// en . wikipedia . org / w / index . php ? title = Example , ▁is ▁generated ▁via ▁URL ▁re writing ▁from ▁the ▁more ▁human - read able ▁external ▁URL , ▁http :// en . wikipedia . org / wiki / Example . ▁ ▁An ▁entry ▁in ▁a ▁blog ▁with ▁many ▁entries ▁is ▁accessible ▁from ▁the ▁site ' s ▁front ▁page ▁for ▁only ▁a ▁short ▁time . ▁Vis itors ▁who ▁store ▁the ▁URL ▁for ▁a ▁particular ▁entry