Missing in the form of dot [letter]

[Taylor Walter]

Hi Statalist, can someone please explain the difference between a simple missing "." and a missing of the form ".n" or ".b" or any letter following the dot? Is there any meaning to the letter(s)?

And is there a succinct way of replacing values of "dot-letter" to just "." for all vars in a dataset? What about for searching all vars to unearth different combinations of "dot-letter" to find where this issue exists in the first place?

[FernandoRios]

This has everything you need to know about "." and ".letter"
help missing

[Nick Cox]

The missing codes .a to .z can mean whatever a user wants them to mean and the meaning can be made explicit by exploiting the scope to define value labels.

Start at

help missing

and click your way to [U] 12.2.1 Missing values.

If you're determined to ignore the codes you received, then you can override with

replace whatever = . if missing(whatever)

or

replace whatever = . if whatever > .

which have the same effect (but not the same meaning).