From Longman Dictionary of Contemporary Englishdittodit‧to1 /ˈdɪtəʊ $ -toʊ/ ●○○ adverb spoken informal1SAMEused to say that you have exactly the sameopinion as someone else‘I hated school.’ ‘Ditto.’2used to say that what is true of one thing is also true of anotherWhere should she go? Mississippi? Too hot. Ditto Alabama.
dittoditto2 (also ditto mark) noun (plural dittoes) [countable] writtenSLAa mark (〃) that you write immediately under a word in a list to show that the same word is repeated
Examples from the Corpus
ditto• Or, possibly, Loopy Old Bats Against ditto.From Longman Business Dictionarydittodit‧to /ˈdɪtəʊ-toʊ/ noun [countable]a mark (") that you write beneath a word in a list so that you do not have to write the same word again