I am looking to analyze missing data so I tried with command mdesc and summ but it came back with no missing data. When I tried codebook it came back with 98 and 99. These are not defined as missing data but rather "don't know" and "prefer not to say." Is this correct? Is this why the mdesc and summ did not show them as missing? Command misstable only works if I conduct multiple impution but does not list out the missing values. Please advise. Thank you.