[R] ordering of alphanumeric strings

[kschlauc]

Can someone tell me which version of R began to order 
alpha-numeric strings in this manner:
"ABC 10" < "ABC 2"
rather than 
"ABC 2" < "ABC 10" ?

And, is there a way to force "ABC 2"
to be ordered as a value less than "ABC 10"?

thank you,
Karen
kschlauc at vt.edu