The Old New Thing

What's the deal with the EM_SETHILITE message?

If you look up the documentation on the and messages, they just say "not implemented". What's going on here? The and messages were added back in 2002 for the breadcrumb bar to use. Back in those days, the breadcrumb bar wasn't what you see in Windows Vista today, a series of buttons with drop-down arrows, each representing a level in the ...