The XTF2_HOME_CTRL and _END_CTRL flags, when used in an editable tree where XTF_HOME and/or XTF_END are not set, allows Home and End to, in some types of editable cells, navigate to the first / last editable cell on the current line. By "some types" we mean essentially any kind of editable cell except one that allows you to directly edit the contents of (i.e. a standard editable text cell), since in the latter case, Home and End are captured by the edit box itself to move the cursor to the beginning and ending of the cell, rather than to move between cells. But for checkboxes, radio buttons, read-only cells, etc., these new keys provided yet another navigational shortcut for power users.
Note that for convenience and perhaps clarity, a symbol has been defined in ashinc:xtree.def:
define XTF2_NAVCOL = &h00000003 ! (XTF2_HOME_CTRL+XTF2_END_CTRL)
Also note that these flags have no effect in non-editable situations, provided the keys are not enabled as exit keys (via XTF_HOME / XTF_END). If they are enabled as exit keys, then the XTF2_NAVCOL flags reverse the action of the simple keys and the keys with Ctrl+. In other words, when set, Ctrl+Home will navigate to the first row, while Home will exit; otherwise, Ctrl+Home exits and Home navigates.
