Seeing some of the comments in this thread, I think it might be wise to have rules/standards for stuff that really matter and classify the rest as something like recommendations. In the end, if you don't have 100% agreement on how something should be done (including when new people join the dev team) it won't get done that way all of the time - and even with 100% agreement, I would bet things like this get ignored any time someone is in a hurry. I've been watching the current commercial project I'm working on bypass the way stuff is supposed to be done time and time again just to get things done faster. And in the end, it only gets fixed if it's going to save time in the future and/or it really annoys one of the developers.
Dennis