I was having trouble with my computer. So I called John, the 11 year
 old next door whose bedroom looks like Mission Control, and asked him to
 come over.. 
 
 John clicked a couple of buttons and solved the problem.
 
 As he was walking away, I called after him, 'So, what was wrong?  
 
 He replied, 'It was an ID ten T error.'
 
 I didn't want to appear to stupid, but nonetheless inquired, 'An, ID
 ten T error? What's that?  In case I need to fix it again.'
 
 John grinned.  'Haven't you ever heard of an ID ten T error
 before?''
 
 No,' I replied.
 
 'Write it down,' he said, 'and I think you'll figure it
 out.' 
 
So I wrote down: I D 1 0 T