Why "cvs commit -r" fail ?

[marshalli . tw]

Hi:
       I use cvsnt 2.5.02.
Though, when I use "cvs commit -r 2.1 xxx.txt"
I got the following exception.

As I find in newsgroup,
cvs seems doesn't support this command any more.

My quesiton is
Why?
And how can I change the revision number from 1.369 to 2.0 ?
Does that mean the first digit will never change to 2 ?

Thank you


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commit: invalid option -- r
Usage: cvs commit [DnRlf] [-B bug | -b bug ] [-m msg | -F logfile]
files...
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Marshalli