In #11243 we ended up resolving to:

• Re-use the grid-* properties for templating and explicit placement.
• Adopt the item-flow proposal (in principle) for flow control. See [css-flexbox][css-grid] Unifying grid-auto-flow and flex-flow #11480

With that context, I'm opening this issue to focus on one specific sub-point of the syntax debate: how do we trigger masonry layout?

The three proposals so far are:

• Use a new display value. Adopted but needs name bikeshedding, see below.
• Use display: grid + grid-template-rows/columns: collapse.
• Use display: grid + item-pack: collapse (allowing it to show up in the item-flow shorthand as .e.g. item-flow: row collapse).

Now that item-flow has been adopted, nobody is advocating for the grid-template-rows/columns option. But people wanted some time to absorb the new item-flow situation before deciding. See https://www.w3.org/TR/css-grid-3/#flow-control

New ideas are also welcome.

UPDATE: The CSSWG resolved to use the display property together with a value that includes the word grid. Currently looking for proposals on what that name should be. It could be grid-something, something-grid, or grid something/something grid (two keywords). Names proposed so far include:

• grid-collapsed or collapsed-grid or grid collapse
• grid-stack or stacked-grid
• grid-pack or packed-grid or grid pack
• compact-grid
• grid-masonry or masonry-grid
• grid-flex or flex-grid
• grid single-axis (masonry grid) vs grid dual-axis (normal grid)
• staggered-grid or grid staggered
• uneven-grid