selection - Manipulate the X selection
http://www.purl.org/tcl/home/man/tcl8.4/TkCmd/selection.html
selection option ?arg arg ...? Supported subcommands are: selection clear ?-displayof window? ?-selection selection?
selection get ?-displayof window? ?-selection selection? ?-type type?
selection handle ?-selection selection? ?-type type? ?-format format? window command
selection own ?-displayof window? ?-selection selection?
selection own ?-command command? ?-selection selection? window
Can someone write up some text distinguishing the terms for 'inter-widget text highlighting for copy/paste purposes' and 'user initiated indication of widget component indication' - in other words, distingushing the concept of 'selecting text in a text widget or whatever' vs 'selecting listbox items'...
See also:
Tk syntax help - Arts and crafts of Tcl-Tk programming - Category Command