There are old posts in the newsgroups showing how to center align text
while right aligning numbers in a cell using the custom number format
"* 0;* -0;* 0;@" and setting horizontal alignment to Centered. The '*
' piece can also be applied in the text portion of the format, e.g.,
"0;-0;0;* @" with General horizontal alignment would right align text.

So what? Could just set horizontal alignment to Right. But in Excel
2007 and later number formats can be included in conditional formats
but alignment can't, so this trick could be used to change text
alignment in conditional formats.