Data Entry - Agricultural Statistical Data Analysis Using Stata - page 53

In addition to the labels, notes can be attached to a dataset or indi-
vidual variables. To attach a label to the dataset, select the menu
Data > Data utilities > Label utilities > Label dataset
To attach a note to a variable, select the menu
Data > Variables Manager
To add a label to the dataset, in the Command window, type
label data: 'type your label'
To add a note to a variable, type
notes varname : your note
To list the notes from the Command window, type
notes
These labels and notes can be added or changed from the Main
window by clicking the lock icon in the Properties region. This will
unlock the variables properties where the label and notes can be
accessed. Click the … button to add additional notes. These addi-
tions also can be made from within the Data Editor window in the
Properties section of this window.