LTI has received a number of queries regarding the processing of form/genre headings in 655 fields given LC's establishment of a new thesaurus for such terms.
Because LTI processing presumes that "650" headings identified for use as genre/form headings will eventually be added to the LCGFT thesaurus, following authorization they are tagged as 655 _7 $a... $2lcgft. This affects all headings formerly authorized in 655 _0.
If LC subsequently establishes a heading in a form different from the one used by LTI, the new LC form becomes the authorized heading and the old form becomes an internal LTI cross-reference to the established LC form.
If you have questions, please contact Marsha Hunt at LTI.