The current MSC Rules can be found at:

http://mymsc.ca/Documents/CMSWSwimmingRules20100307.pdf
http://mymsc.ca/Documents/CMSWReglements20100408.pdf

Most changes are clarified wording, the only actual change to the rules concern butterfly:

CMSW 8.2 Both arms shall be brought forward together over the water and brought backward simultaneously throughout the race, subject to CMSW 8.5. Continuous kicking in a layout position is not allowed, subject to CMSW 8.5.

CMSW 8.3 All up and down movements of the legs must be simultaneous. The legs or the feet need not be on the same level, but they shall not alternate in relation to each other. A breaststroke kicking movement is permitted for butterfly. Only one breaststroke kick is permitted per arm pull except that a single breaststroke kick is permitted prior to the turn and the finish without an arm pull. After the start and after each turn, a single breaststroke kick is permitted prior to the first arm pull.

These rules were approved by the MSC Board on March 7th, 2010.

The above rules should be used for all Masters Swimming Competitions in Canada.

http://mymsc.ca/Documents/Open_Water_Rules_May_10_2009.pdf
http://mymsc.ca/Documents/Natation_Eau_Libre_10_Mai_2009.pdf

Appendix C: Masters Swimming Rules in the SNC Rule book (2005) have been superseded and should not be used for Masters competitions in Canada.

FINA Masters Swimming Rules 2009 - 2013 (a list of differences from the FINA Swimming Rules)