status code 100 (continue)

The way I read section 8.2 (message transmission requirements) is: 
 
IF ((client is 1.1) AND (NOT connection:close)) then I MUST send 
status 100 or an error. 
 
Will clients get confused receiving 100 even if connection:close? 
 
Do I *really* have to send a Date header? 
(Well, according to 14.19 I do, but that is for caching, and as far as 
I can tell, only terminal stupidity - in the form of a cache-control 
directive - will cause a 100 response to be cached). 
 
And, (once again) what is the rationale for the 100 response? 
It seems unnecessary and wasteful; what am I missing here? 


Thank You, 
Richard L. Gray