Income-tax rules amendment expands rule three proviso to include airline employees alongside railway employees, changing applicability. The amendment substitutes the proviso to rule three of the Income-tax Rules, 1962 to replace the reference to the Railways with a reference to an airline or the Railways, thereby extending the proviso's applicability to airline employees; the rule is enacted as the Income-tax (Third Amendment) Rules, 2003 and is deemed to have come into force on the first day of April of the relevant year.