Surround your tabs with these tags, substituting straight brackets for the curly ones shown here:
{pre}your groovy tab stuff{/pre}
If the end result is too small, then surround all that text with these size tags, using 3 or 4 as your size:
{size=4}{pre}your groovy tab stuff{/pre}{/size}
If you use the Teletype function, see the

button when you post, it will place these tags around your tab and make it line-up properly. It's so small, you'll need to increase the size a bit, as Mr. A suggested.
Example:
[tt]R L R L[/tt]
would look like this when posted:
R L R LThis is what I use, and increase the font size to 3, which would look like this:
R L R LOr increase to 4:
R L R LAnyway, it all lines up now as you add various lines in your tab notation. You can also use
bold,
italic, and
colors as needed.