GG's response to Glenn in the forum seems (https://www.cinelerra-gg.org/forum/help-video/hotkey-to-deselect-all-groups/...) so clear and interesting to me that I propose to include it in the latex manual: GG on selection's method: [at the end of paragraph 5.5; as a final summary. then becomes a new paragraph 5.6 and the following are moved to 5.7, ... etc. I'd like to name the section: "Good Guy speaks:"] There are several "selections" method. First, in the olden days, there was the column oriented timeline drag selection. That manifests in 1 of 3 ways. a highlighed vertical column, a single flashing line, or the blue line region between the [in and ]out marker labels. When the drag column is in use, it has the highest precedence and is used for selection. When the column is a single line, then the fall back selection is the [in/out] marker region, if they are set. When they are not set, and the cursor is flashing, then the selection start=end and the selection is empty, but it does have a position on the timeline which can be used for editing. This is input for the vertical style cut/paste drag/drop editing. Now, in the new "group" world, there are "edit" selections. These are created by using the drag/drop cursor and clicking edits to toggle select/deselection. These are input to a different (more modern) set of cut/paste/overwrite drag/drop editing. These are the set of operations you see when you click an edit with the middle mouse button, and are available using the hot keys which are more like text editor, ^x=cut, ^c=copy, ^v=paste, and so on... The delete key is not hooked to these operations. It is hooked to the cursor selection region. If there are In/Out points, they enter the selection priority queue between the column selection and the cursor only. You can see the region selection blue line across the timebar. This means that when the cursor selection is empty, the in/out selection will be used.