Methods and apparatus for generating electronic records of marking operations for underground facilities/utilities. Electronic records of marking information may be logged/stored in local memory of a marking device, formatted in various manners, processed and/or analyzed at the marking device itself,...http://www.google.com.hk/patents/US20100086677?utm_source=gb-gplus-share專利 US20100086677 - METHODS AND APPARATUS FOR GENERATING AN ELECTRONIC RECORD OF A MARKING OPERATION BASED ON MARKING DEVICE ACTUATIONS
