OpenACC: present clause and 'enter data'

May I ask how far the support for ‘enter data/exit data’ is? When using it together with a present clause (which I find useful just for failsafe reasons), I’m getting the following error:

PGF90-S-0533-Clause ‘PRESENT’ not allowed in ‘ACC ENTER DATA’ directive

Will this be supported in the future or is it simply not part of the spec?

I just ‘rtfm’ and indeed it’s not in the spec, so nevermind my question, the info is all there:

http://www.openacc.org/sites/default/files/OpenACC%202%200.pdf

enter data clause-list
where clause is one of the following:
if( condition )
async [( int-expr )]
wait [( int-expr-list )]
copyin( var-list )
create( var-list )
present_or_copyin( var-list )
present_or_create( var-list )

exit data clause-list
where clause is one of the following:
if( condition )
async [( int-expr )]
wait [( int-expr-list )]
copyout( var-list )
delete( var-list )