In the following procedure one receipt code is being eliminated using <>. How can I change this to eliminate (exclude) two codes?

select NVL(sum(rc_amt), 0)
into tot_cont
from trefrc
where rc_filer_seq = filer
and rc_ceipt_code <> 13;

I want to exclude another code, 19. How can I best accomplish this?

Thank you, Jim