QuartusII - Missing drive strength and slew rate

Hi all,

in a complete project compilation, I solved all errors and warnings;

there remains only this:

warning: some pins have incomplete i/o assignments. refer to the i/o assignment warnings report for details

watching on the PIN assignment, I see this on all output PINs:

missing drive strength and slew rate

but the strange thing is that on the slew rate column of the pin report, I see those PINs with the slew rate value of "2(default)", assigned by Quartus by default.

What can I do to remove this last warning?

Thanks to all