True allergies to cow's milk are relatively uncommon. Only 2 to 3 percent of children are allergic to milk, according to the AAP, and almost all of them outgrow it by age 3. (Learn the difference between a milk allergy and lactose intolerance .).
The underscore [ _ ] (also called underline, underbar, low line, or low dash) is a character that originally appeared on the typewriter and was primarily used to underline words.
The system also provides a field for Description, though not everyone uses it. Macro names must begin with a letter and cannot contain spaces, symbols, or punctuation marks. After the first letter, you can use more letters, numbers, or the underscore character, but the maximum length is 80 characters.