Stata requires us to provide the maximum size of a charactervector as every row is stored in a bit region of this size.
maxchar(x)vector of data frame
Ex: If the max chars size is four, _ is no character in this vector: 1. row: four 3. row: one_ 4. row: ____
If a character vector contains only missings or is empty, we will assign it a value of one, since Stata otherwise cannot handle what we write.