Complex sentence: Because of the risk of ambiguity in allocating oxidation states, IUPAC prefers direct indication of the ionic charge numbers written in parentheses directly after the name of the cation (without a space separating them).
Split into simpler sentences: Because of the risk of ambiguity in allocating oxidation states, IUPAC prefers direct indication of the ionic charge numbers. These are written in parentheses directly after the name of the cation (without a space separating them).