THE Reference - SET Commands

SET SELECT - sets the selection level for the specified lines
Syntax:: [SET] SELect [+|-]n [target]
Description:: The SET SELECT command sets the selection level for the indicated lines equal to n (if no signs are specified) or adds or subtracts n from the selection level currently set for the lines in the target.
Compatibility:: XEDIT: Compatible.; KEDIT: Compatible.
Default:: 0
See Also:: SET SCOPE, SET DISPLAY, ALL
Status:: Complete.