Bug introduced in 9.0 or earlier, persisting through 13.2 or later
There is an example in the Alignment documentation (it also appears in the Grid documentation):
Grid[{{Graphics[Rectangle[], ImageSize -> 20], Graphics[Rectangle[], ImageSize -> 30]}, {Graphics[Rectangle[], ImageSize -> 40], Graphics[Rectangle[], ImageSize -> 50]}}, Alignment -> {{Right, Left}, {Bottom, Top}}] 
The Alignment documentation indicates that numbers can be used for the alignment. Therefore the example above should be able to be re-written as
Grid[{{Graphics[Rectangle[], ImageSize -> 20], Graphics[Rectangle[], ImageSize -> 30]}, {Graphics[Rectangle[], ImageSize -> 40], Graphics[Rectangle[], ImageSize -> 50]}}, Alignment -> {{1, -1}, {-1, 1}}] However this has no effect:

So what is the correct way to use numbers for Alignment?


Grid(as you use) it does not support the individually two-dimensional alignment specifications. $\endgroup$Alignment->xorAlignment->{x,y}. But I can't get even that to work. $\endgroup$Right, -1 forLeft, -1 forBottomand 1 forTopand get the same result. $\endgroup$