Grid: Key "Space" to select a cell is missing

[JAWS-test]

https://w3c.github.io/aria-practices/#grid:

If a grid supports selection of cells, rows, or columns, the following keys are commonly used for these functions: Control + Space: selects the column that contains the focus.

First, "Space" should be mentioned to select a cell - at least in cases where the focused cell is not identical to the selected cell. This is especially important when I can select several cells that are not adjacent (so that Shift+Arrow does not work).

[a11ydoer]

Grid project

[css-meeting-bot]

The ARIA Authoring Practices (APG) Task Force just discussed Grid issue.

The full IRC log of that discussion

<carmacleod> TOPIC: Grid issue
<carmacleod> https://github.com//issues/2195
<carmacleod> Matt_King: Are we talking about the pattern or the examples, because we don't have any examples yet.
<carmacleod> jamesn: The pattern. We don't say how to select a cell.
<carmacleod> Matt_King: You can operate on selected items, or on focused items if there is no item currently selected.
<carmacleod> Matt_King: You could implement contiguous selection, but not in a grid where cells are editable.
<carmacleod> jamesn: Having space be used to toggle selection would be useful.
<carmacleod> Matt_King: I think we do need to edit the pattern.
<carmacleod> Jem: So, editorial?
<jamesn> github: https://github.com//issues/2195
<carmacleod> Matt_King: More than that, because it's modifying the guidance

[a11ydoer]

additional information for grid selectioin model is needed.