Development and Maintenance Loading

I am interested in seeing guidelines used by coaches here as to loading used in the development of a characteristic (speed, strength, etc.) and the loading used to maintain the characteristic. For example: one rule of thumb that I have heard over the years is that in strength training (development) the number of repetitions done per exercise per day should range between 10 and 35. Any less than 10 total repetitions in an exercise is too few to give a training effect and any more than 35 total repetitions leads to overtraining and is too many to give a positive training effect. These were excluding warm-up repetitions. I have also heard a rule of thumb stated that to retain a characteristic (speed, strength) that volume is reduced to 50-60% of developmental volume and intensity is reduced to 80-90% of maximal intensity (depending upon the characteristic). Please note that these are not my guidelines, these guidelines have been purported by other top strength and conditioning professionals in either articles or presentations.