[ Type code = Y ] Default to (and pre-display as) "Y", unless followed by a N code, or followed exclusively by an E or T code. (This is to maintain compatibility with INPUT's YE and YT.) The keyboard character "1" is interpreted as (and converted to) "Y" and "0" as "N" in Yes/No fields. Note that the English "Y" and "N" abbreviations may be changed by the language definition file (LDF) to more appropriate ones for the local language.
See the GUI-Related Codes topic for information on converting a Yes/No field to a checkbox.