Dear Michael,
The updates have been made.
The registry now reads:
art-lojban Lojban [Cowan] Deprecated
use ISO
639-2 jbo,
registered
Sept. 2,
2003.
i-klingon Klingon [Everson] Deprecated
use ISO
639-2 tlh,
registered
Feb. 24, 2004.
Best regards,
IANA