Definitions for Different Missing Value indicators

[luzhang714]

In the data, when I ask for missing values, the output looks like
.
D
E
R
which are all missing values.

It'd be .m, .d, .e, .r in STATA.
I'm wondering what these codes indicate for the reason of missing-ness.
I assume "D" is don't know, and "R" is refused to answer, but wouldn't know what "E" is.
Is there documentation somewhere that has this information?

Thank you.

[econwang]

.e .E表示根据逻辑跳转不需要回答