Dress code for breakfast and lunch is casual. There are no irons in cabins but better still there are free laundrettes on most decks which includes irons. There is a kettle and coffee/tea/biscuits facility in cabins. There is one UK type power socke.
There are special safety irons in suites and minisuites but other than that irons are not allowed in cabins. As the previous answer said there are launderettes on each deck which have about 4 ironing boards and irons. You can send things to the laundry to be washed and ironed or just pressed.