“…They are syntactic, lexical and structural features. The various lexical features are content words, letter frequency, special characters , character n-grams, misspellings in [10,11], special use words in [12], 8 punctuation marks in [13], most frequent types [14], spelling errors, word form errors in [15], syntactically classified punctuation , syntactic structure [16], function word frequencies, POS trigrams or sequences of 3 in [17], word n-grams in [18], POS bigrams or sequences of 2 in [19], unigrams/types shared by training and testing samples in [20], 1024-character sequences in [21], content words, frequent words in [22], words bigrams or sequences in [23], emoticons, netabbrevs in [24], character n-grams or sequences in [25], non-function words in [26], frequency of lemmas (dictionary entry headwords), frequency of negative words in [27]. The various syntactic features are punctuation, function words [10], POS tags [11], syntactically classified punctuation, verbal phrases [15], syntactically classified punctuation [16], function word-token ratios [28], POS trigrams or sequences of 3 [17], punctuation frequency [18], POS bigrams or sequences of 2 [19], PCFG-obtained POS [26], syntactically classified punctuation [29], verbal phrases [30], phrase types, words per phrase type [31].…”