INSERT OVERWRITE TABLE with IF NOT EXISTS

[Eugene Koifman]

Hi,
According to 
https://cwiki.apache.org/confluence/display/Hive/LanguageManual+DML#LanguageManualDML-Syntax.1
 we support
INSERT OVERWRITE TABLE tablename1 [PARTITION (partcol1=val1, partcol2=val2 ...) 
[IF NOT EXISTS]] select_statement1 FROM from_statement;


What might the intent of IF NOT EXISTS be here?

Thanks
Eugene