Methods, apparatus, and systems for facilitating a marking operation to indicate a presence or an absence of at least one underground facility. Marking information relating to the marking operations, including one or both of environmental information representative of at least one environmental condition...http://www.google.com/patents/US20100247754?utm_source=gb-gplus-sharePatent US20100247754 - METHODS AND APPARATUS FOR DISPENSING MARKING MATERIAL IN CONNECTION WITH UNDERGROUND FACILITY MARKING OPERATIONS BASED ON ENVIRONMENTAL INFORMATION AND/OR OPERATIONAL INFORMATION
