I'm not sure whether these have been featured on BP, but anyway here
they are:
AT2BLNOST (Burgenland - Lower Austria - Styria):
http://www.fhs-pi.asn-bgld.ac.at/pdf/innovativ/nl_04_00.pdf
(Look for the picture on page 16, below the caption "FH-Tag")
And this absolute beauty:
ATDE2BYSBTI (Bavaria - Salzburg - Tyrol):
http://www.steinplatte.co.at/sommer/images/so_2.jpg
Peter S.
BTW: I made up these federal land abbreviations (except for BY, which
is official). ISO uses numbers instead of letters for Austrian
federal lands. ISO doesn't consider the fact that we use their codes
in our notation. I wonder why?... :-))