In ideal topological spaces, $\star$-dense in itself
subsets are used to characterize ideals and mappings. In this
note, properties of ${\cal A}_{\cal I}$-sets, ${\cal I}$-locally closed sets and
almost strong ${\cal I}$-open sets are discussed. We characterize
codense ideals by the collection of these sets. Also, we give a
decomposition of continuous mappings and deduce some well-known
results.