First Law of Revision:
  Information necessitiating a change of design will be
  conveyed to the designer after - and only after - the
  plans are complete.
  (Often called the 'Now They Tell Us' Law)

Second Law of Revision:
  The more innocuous the modification appears to be, the
  further its influence will extend and the more plans
  will have to be redrawn.

Corollary to the First Law of Revision:
  In simple cases, presenting one obvious right way versus
  one obvious wrong way, it is often wiser to choose the wrong
  way, so as to expedite subsequent revision.

LAWS OF COMPUTER PROGRAMMING:
I.  Any given program, when running, is obsolete.

LAWS OF COMPUTER PROGRAMMING:
II. Any given program costs more and takes longer.

LAWS OF COMPUTER PROGRAMMING:
III. If a program is useful, it will have to be changed.

LAWS OF COMPUTER PROGRAMMING:
IV. If a program is useless, it will have to be documented.

LAWS OF COMPUTER PROGRAMMING:
V. Any program will expand to fill available memory.

LAWS OF COMPUTER PROGRAMMING:
VI. The value of a program is proportional to the weight
    of its output.

LAWS OF COMPUTER PROGRAMMING:
VII. Program complexity grows until it exceeds the capabilities
     of the programmer who must maintain it.

LAWS OF COMPUTER PROGRAMMING:
VIII. Any non-trivial program contains at least one bug.

LAWS OF COMPUTER PROGRAMMING:
IX. Undetectable errors are infinite in variety, in contrast to
    detectable errors, which by definition are limited.

LAWS OF COMPUTER PROGRAMMING:
X. Adding manpower to a late software project makes it later.

Lubarsky's Law of Cybernetic Entomology:
  There's always one more bug.

Shaw's Principle:
  Build a system that even a fool can use, and only a fool
  will want to use it.

Law of the Perversity of Nature:
  You cannot successfully determine beforehand which side of
  the bread to butter.