Alpha Timing

Alpha Timing is a practice used to make some parts of text appear later than others.
Some groups started to use it for dialogue lines that had a pause in them.

For example a line like "Are you... serious?" would have a pause in the middle.
With regular timing you can read the rest of the line before the character says it,
which can sometines reduce dramatic effect, so you may want to avoid it,
and splitting this into 2 lines might be a bit too weird.

So what you do is make the "serious" part appear only when the character says it,
while the start of the sentence stays in the same place. The way to do it is this:

Dialogue: 0,0:00:00.00,0:00:01.00,Default,,0,0,0,,Are you... {\alpha&HFF&}serious?
Dialogue: 0,0:00:01.00,0:00:02.00,Default,,0,0,0,,Are you... serious?

First line timed to first second, second to the second (no puns intended).
Basically it makes the latter part of the line invisible, but since it's technically there,
you don't have to change the positioning of the line.

Sometimes this is also useful for typesetting, like when a period or an exclamation mark
appear later than the rest of the text.

Of course this also works with more than just 2 segments:

Dialogue: 0,0:00:00.00,0:00:01.00,Default,,0,0,0,,Weird{\alpha&HFF&}...
Dialogue: 0,0:00:01.00,0:00:02.00,Default,,0,0,0,,Weird.{\alpha&HFF&}..
Dialogue: 0,0:00:01.98,0:00:02.98,Default,,0,0,0,,Weird..{\alpha&HFF&}.
Dialogue: 0,0:00:02.98,0:00:03.98,Default,,0,0,0,,Weird...

Be aware that a lot of people hate alpha timing for dialogue, mainly because some groups,
like Lunar, abused the shit out of it and used it almost like karaoke.