Hey guys i found this.. its pretty interesting. Study guide for the MRT. You don't have to be part of USRSA to read it http://www.racquettech.com/certification/studyguide.html I have a few questions from it. After it gets to rules of tennis it gets pretty boring but the first half is interesting and related to stringing. The following is a paragraph taken from the guide: "These include: alternating tensioning of mains (no more than 3 strings ahead on one side), pulling one string at a time, avoiding notching of mains during weaving, installing pattern specified by manufacturer, avoiding crossovers at the head, avoiding any mis-weaves in string face, turning in a frame without cracks or broken/cracked/unseated grommets, completing the bumper/grommet removal and replacement within 20 minutes, completing the string job within 60 minutes, and completing the handle sizing/grip replacement within 20 minutes." 1. What does notching of the mains during weaves mean? 2. What is crossovers at the head? 3. How do you do the bumper grommet remover? and wow it takes 20 minutes? and how do you do the handle sizing/grip replacement?