mosar is not law it is a guideline and one limited to wikipedia at that and frankly only if at least of all references in english had used the spelling harun al rashid is a meaningless argument because you apply double standards meanwhile in the actual world prevalent usage is both clear and supported by the best of sources sorry but in my opinion carries no weight when an array of first class academic references is perfectly happy to use the al form wikipedia follows usage it does not create it i sympathize with striving for phonetic accuracy in transliterations but this is a case where usage is so overwhelming that this debate is pointless anyhow long story short if you don't agree with keeping the old name this calls for a wp rm