I've heard it recommended that you should lock down the OOTB site
columns and content types so users can't modify them. At the same
time, I've heard that you shouldn't edit OOTB Features and definitions,
but create new ones instead. I'm having trouble reconciling these two
recommendations. The only way I can find to lock down existing site
columns and content types is by marking them "Sealed=TRUE" in the
Features where they are defined. Is this the only way to do this?