Dima: In Nicolas's "Ludum Dare 25" entry, the font is loaded from a SWF lib (Look at the "obj" directory, there is "ld25Resources.swf" file, containing the "PixelFont" used in the entry), not from the font found in "gfx" directory. He isn't using any macros for loading the font, only the -swf-lib compiler argument and the "h2d.Font" class.
Simon: Don't know if you are talking about the metadata for embeding resources in a swf, but here you may find information about them:
http://haxe.org/manual/tips_and_tricks#flash-specific-metadata. Perhaps you refer to something else.