restriction
     n 1: a principle that limits the extent of something; "I am
          willing to accept certain restrictions on my movements"
          [syn: {limitation}]
     2: an act of limiting or restricting (as by regulation) [syn: {limitation}]
     3: the act of keeping something within specified bounds (by
        force if necessary)
Source: WordNet® 2.0

restriction n. A {bug} or design error that limits a program's
   capabilities, and which is sufficiently egregious that nobody can quite
   work up enough nerve to describe it as a {feature}. Often used (esp. by
   {marketroid} types) to make it sound as though some crippling bogosity
   had been intended by the designers all along, or was forced upon them by
   arcane technical constraints of a nature no mere user could possibly
   comprehend (these claims are almost invariably false).

   Old-time hacker Joseph M. Newcomer advises that whenever choosing a
   quantifiable but arbitrary restriction, you should make it either a
   power of 2 or a power of 2 minus 1. If you impose a limit of 107 items
   in a list, everyone will know it is a random number -- on the other
   hand, a limit of 15 or 16 suggests some deep reason (involving 0- or
   1-based indexing in binary) and you will get less {flamage} for it.
   Limits which are round numbers in base 10 are always especially suspect.


Source: The Jargon File