Boulder Dash Forum

In the BDCFF-document, I noticed that the butterfly
and firefly elements come in four different flavors,
they're postfixed with either 'd', 'l', 'u', 'r'.

I assume that this has something to do with the direction
they follow if they're in 'open space', (that is, not surrounded
by any other element).

Is this correct or has it another or broader meaning ?

This indicates the starting direction of the element.

Names ending with "l", "r", "u", "d" (except for a succeeding "d") indicating the direction.

Thanks for the answer.

Can you please tell me where this quote is coming from ?
I think it would be interesting to read all of it.

You're welcome.

Sorry, can't find the webpage anymore. I think that it has been removed. I only have the sites offline.

But I can give you a link to Marek's webpage. I think the content is almost the same. So this should help you.
BDCFF extension for Crazy Dream PC

If you want to get more information, just search the web or this forum for "BDCFF".