see also : man chflags"There does exist another layer of markers on the filesytem, that you don't tend to run into very often. [T] is encouraging you to read the man page for the ufs tool, chflags, which gives access to things like "immutable flag". I suspect [T] has learned that "finder info" is actually working on filesystem flags.
"You can further make things painful by running most BSD's in a state where flags cannot be changed (I've never done it). This means that if you install your new kernel in single user, flag it as immutable, and run the system in secure mode: you will force any intruder to put the system into single user before /kernel (and any other binaries so flagged) can be changed or deleted."