[ Thanks to Brendan Scott for this
link. ]
“Maintain Separation of Projects
“A failure to properly structure your files (whether physical or
electronic) can have legal implications. For example, if you fail
to maintain a clear demarcation between the open and closed source
work that you do, the code from one area may contaminate the other,
potentially leading to untold heartache. Indeed, this applies
pairwise to any two projects you are working on. Particularly
important is that you maintain a strict demarcation between any of
your personal coding infrastructure (eg common libraries that you
may have developed and reuse for multiple clients) and the specific
projects you are working on.”