Length of public exponent in OpenPGP card specification

[Klaus Flittner]

Hello,

in the specification[1] the algorithm attributes contain a field for
the length of the public exponent. The available implementation of the
card[2] has a fixed value of 32 bits, but key import accepts a value of
65537 (17 bits) and key generation also produces only keys with e of
65537. What is the use of this field then?

Regards
 Klaus Flittner

[1] http://www.g10code.com/docs/openpgp-card-2.0.pdf
[2] http://shop.kernelconcepts.de/product_info.php?cPath=1_26&products_id=42