Certainly more guidelines than rules.
McLachlan
Robert I
RI
D000368:Aged; D000375:Aging; D000728:Androgens / Q000172:deficiency; D017408:Guidelines as Topic; D006801:Humans; D007006:Hypogonadism / Q000188:drug therapy; D008297:Male; D013739:Testosterone / Q000009:adverse effects / Q000172:deficiency / Q000627:therapeutic use*
D000728:Androgens; D013739:Testosterone