>>If you implement more options than !empty() via the char field, you are already well along the slippery slope of magical constants -
>>the usual remedy being a lookup table with text and perhaps logic to be balanced against existing fwk support and update frequency.
>
>This particula field right now will have just to values, 'Y' and 'N'. The database default will set the value 'Y' and user could change it to 'N'. That is all.

You're lucky that you can do so. Most often, such a field is an afterthought, when you already have trucks full of records in such a table, and you can't rely on having the value in old records properly filled in. So you go with .f. being a default for new boolean field in old records, and then name it so that the value of .f. is the default. Thus my forced choice for such fields is "Inactive", "Deleted", "Removed" and such words with implied negative.