Bumper question

[mikeb98]

Is making a rabbet joint on the end of a bumper against the rules (rule 21 a specifically)? This would mean that part of our bumper is approximately 3/16in thick instead of the required 3/4in thickness, but our other bumper that is connected to the joint will give it the 3/4in thickness. Here is an example of what it would look like: http://www.woodworkersjournal.com/wp...ple-Rabbet.jpg

Also, are we allowed to add a metal segment on top and bottom of the bumpers so it forms triangular supports on the top and bottom? Here is another example: http://www.brickshelf.com/gallery/ca...sc/bracing.jpg

Sorry if my wording is confusing, and thank you!